AFR Installation Instructions

Read our instructions before installing your AFR product.
Click your product below to view the instructions.



Titon Manifold

    Installation Instructions

  1. (CLICK HERE)


Small Block Chevy Aluminum Cylinder Heads

    Installation Instructions

  1. ATTN: Please read through all instructions before attempting cylinder head installation.

    Springs: It is the customers responsibility to check and make sure that spring pressures are correct for his Cam

    Valve Guide Clearance: Intake & Exhaust guide clearances are .00125. On some severe applications with heavy nitrous, marine or blower usage, looser guides might be required, looser guides isn't an option AFR offers.

    Important: Apply anti-seize to all bolts and spark plugs to ensure a long thread life.

    *WARNING* Piston dome to cylinder head clearance must be checked prior to final assembly of engine.

    Valve Tips: Do not grind your valve tips. Some AFR heads have harden stellite tips which cannot be re-ground. If groud the tip will mushroom over causing severe damage. If your valve tips are magnetic you can grind a maximum of .015 from the tip.

    Cleaning:

    AFR thoroughly cleaned your cylinder heads prior to shipment. Your heads were washed in water soluble chemical agitation tank and blown out with high pressure air 3 to 4 times before they were boxed. However during some machining operations chips are packed and wedged into the water jacketing and occasionally come loose in transit. Keep in mind one chip the size of a dime breaks into hundreds of tiny chips and makes the situation appear much worse than it is in reality. It is not usually if you blow high pressure air into the water jacketing to see additional foreign debris, or chips finding their way out. AFR recommends that you thoroughly blow out your heads prior to installation.

    2) Head Gaskets:

    Fel Pro #1003 for all aluminum heads up to 4.100 bore. Fel Pro #1034
    should used for 4.100 or larger bore. Applications requiring steam holes should use Fel Pro #1014. Late Model LT-1 reverse cool applications use GM gaskets or Fel-Pro #1074. AFR has removed the cooling passage between cylinders 1 & 3 and 5 & 7 to increase strength of the casting, do not drill these areas out in an attempt to find water jacketing.

    3) Intake Gaskets:

    Important: Do not port match you intake manifold to these below gaskets, as they do not exactly fit AFR cylinder heads. AFR #6820 or Fel Pro #1206 standard gaskets should be used for 210, 227, 235, & 245 heads. Fel Pro #1205 gaskets should be used on the 195cc heads, excluding the 195cc competition package which should run Fel-Pro #1206. This gasket is a trim to fit style. We recomend AFR #6817 Fel-Pro #1256 for 180cc heads. A small amount of silicone is recommended around the water ports and on the bottom of the intake ports. For late model 180cc LT-1 reverse cool applications use GM gaskets or Fel-Pro #1284, for AFR 195, 210, and 227cc LT-4 use AFR #6860. On some applications it is advisable to eliminate the cork end gaskets and use a bead of silicone instead. Do not port match your intake manifold to these gaskets!!!!

    4) Exhaust Gaskets:

    Fel Pro #1404 exhaust gaskets should be used on all street heads (180 & 195). With minor trimming Fel Pro #1406 may be used on the 210, 220, 227, & 235 standard exhaust heads. For spread ports #1409 should be used. Do not under any circumstances port match exhaust ports to match gaskets. Reverse cool applications use GM gaskets only.

    5) Valve Cover Gaskets:

    Fel-Pro #1604 double thick cork with steel core is recommended.

    6) Head Bolts & Washers:

    Quality relief ground bolts or studs are preferable. You must
    use a washer between the head and the fastener to prevent galling.

    7) Head Bolt Torque:

    All aluminum cylinder heads should be torqued to 65-70 ft/lbs. This should
    be done in the proper General Motors sequence in 10 ft/lbs increments beginning at 40 ft/lbs. Moly lube should be applied between fasteners, washers and areas around head bolt to prevent galling and improper torque values. All high compression, supercharged, turbocharged & nitrous motors should receive a retorque after the first run-in and complete cool down. Bolts containing a 12 point head are suggested in 3 areas on each head near the exhaust valve springs where it may be difficult to fit a standard 5/8 hex head socket. In case of head studs, use 12 point nuts. Airflow Research stocks complete and partial head bolt kits, studs and washers for your convenience. Proper ARP #'s for head bolt kit use #134-3701 and head stud kit use #234-4301. Sealer should be applied to all threaded areas that enter into the block water jacketing, Permatex is a good general purpose sealer.

    8) Rocker Stud Location:

    Airflow Research cylinder heads feature two rocker arm stud locations, standard G.M. and an offset (for maximum intake port volume). The 180, 195, 210, & 220 heads all use the standard G.M. L98 stud location. The 227 & 235 heads use the offset location which will require a matching stud girdle. Airflow Research stocks both standard and offset girdles and adjusting nuts for your convenience. The 245cc is a shaft mount rocker system only.

    9) Guide Plates:

    Use only the guide plates supplied by Air Flow Research! Push Rod Guideplates are supplied with each set of AFR Aluminum Cylinder Heads and installed correctly as shipped. Studs should be torqued to 60ft./lbs. Silicone sealer is recommended on aplications where the stud hole intersects the intake port.

    *IMPORTANT*

    5/16 thick wall Chrome Moly heat treated push rods should be used to avoid wear of the pushrod from contact with the guide plate. If using a tall lifter/short pushrod (6.150 0.L.) combination the 227 will require some clearancing near the head deck surfact. Do not clearance any higher than needed or you will break into the intake port.

    10) Pushrod Lenght:

    This seems like an easily answered question, however, there are many variables. Block and cylinder head deck heights, head gasket thickness, varying cams, rocker arms, and valve length can all affect pushrod lenght. Please see our follow best estimates. for 180 and 195cc heads typically a standard or .100 long pushrod works. For 210, 220, 227, 235, & 245cc typically a .100 or .200 long pushrod will usually achieve proper geometry. For exact pushrod length we suggest using an adjustable pushrod to determine the proper lenght pushrod to be used. For detailed information on pushrod lenght, please view the FAQ section of our website.

    11) Rocker Arms:

    The Airflow Research 180, 195, 210, & 220 aluminum cylinder heads are designed to use standard push rod location rocker arms. (Offset rockers are not required). For AFR 227cc & 235, some applications require shaft mount rockers or .050 offset rocker arms for durability and reliability of valve train. Clearance between rocker arms and the retainers should be checked. For high RPM stability, the Jessel or T & D shaft systems are recommended. AFR offers a complete line of standard and shaft rocker arms for your convenience. AFR suggests for the 227cc/235cc use a shaft mount rocker and offset lifters or at a minimum .050 offset intake rockers. With the .050 offset the intake rocker arms will be at a slight angle and the roller tip will not be perfectly parallel or centered on the valve tip. The 245cc only accepts a shaft mount rocker system with an .180 offset intake lifter required. If you are using Comp. Cams 3/8 Pro Magnum rocker arms you will need to use a longer stud (AFR #6409) because of the thicker trunion on this rocker arm.

    Important Note:

    Do not use late model rocker arms containing side rails as they will conflict with the AFR guide plate.

    12) Valve Seats:

    Both intake and exhaust valve seals are heat treated and compatible with unleaded fuels.

    13) Spark Plugs:

    (14mm x 3/4" gasket) no tapered seat style. For race applications Champion C59YC Autolite 3910 or 51, A/C R41 CXLS & NGK R5672A-9 is a good starting point. For street applications use AC FR3LS, AC 41629, or Champion RC9YC spark plugs or equivalent. Plug selection is of course dictated by many factors including rpm level, compression ratio and type of fuel. All the above plugs are a starting heat range, blowers or nitrous application usually 1 to 2 heat ranges colder. Spark plug gap should be determined by the ignition manufacturer.

    14) 400 Blocks:

    Steam holes are recommended for all 400 block applications. Use a 400
    gasket as a template and drill the three holes nearest the spark plug side of the head straight down, the other three which are very near the head bolt holes should be drilled at a 30 degree angle away from the bolt hole. The center hole will intersect water about 1" down and the two outboard holes to a depth of 2 1/4". Use a 1/8 drill.

    Comoression ratio and piston to valve clearance must be checked before final assmebly

    15) Coolant:

    It is important to maintain a 50/50 mix of antifreeze in the cooling system to
    prevent corrosion of aluminum heads. Don't use tap water use distilled water, most supermarkets have purified or distilled water. Check labeling to verify purified through deionization.

    16) Air conditioning & Alternator Brackets:

    Late model vehicles with one piece brackets that bolts to the block and cylinder heads, may find it necessary to elongate the holes in the brackets to obtain proper hole alignment. Severe production variances from the O.E.M. as well as block and cylinder head milling will all affect this relationship.

    17) Porting Instructions:

    Polishing ports will not improve performance. The center head bolt hole and push rod cross section in intake ports are very thin/maximized from AFR.

    18) Torquing:

    We suggest not using a torque wrench on intake and exhaust manifold bolts, accessory bolts, or spark plugs. Inaccurate torque wrench values can easily strip the smaller threads. Just snug up hand tight with a wrench only.

    19) Intake Manifold:

    Pre-Eliminator (2006 and before) AFR 210 & 227s have extra material on the intake interface of the heads. This raises the intake manifold approximately 3/16" higher than normal. Make sure that your oil pump rod properly engages the oil pump and that your cam and distributor gear alignment is correct. Also a large gap might be present between the end rails of the block, AFR sells spacers to remedy this.

    20) Valve Tips:

    Do not grind your valve tips. Some AFR heads have harden stellite tips which cannot be re ground. If ground the tip will mushroom over causing severe damage. If your valve tips are magnetic you can grind a maximum of .015 from the tip.


Big Block Chevy Aluminum Heads

Installation Instructions

AFR would like to congratulate you on your purchase of the highest flowing and strongest castings currently offered in a “production” style BB Chevrolet Cylinder Head. These heads, properly installed and maintained, will generate impressive power figures and provide you with years of trouble free service. The following instructions and guidelines are meant to assist you in the proper installation and set-up of your new cylinder heads. It is important that you read through all of this information before attempting installation!!

Inspection:

Check all machined surfaces for nicks, burrs, etc., that might have occurred during shipping or storage. If necessary, carefully dress with a file, or sandpaper supported flat by a straightedge. This is especially important on the head deck and intake manifold flange to have an effective trouble-free gasket seal.

Valve Springs:

It is the customer’s responsibility to check and make sure that spring pressures are correct for his/her camshaft application. We recommend a minimum of .060” clearance from coil bind at full valve lift.

Valve Guide Clearance:

Our typical valve guide clearances are .0013-.0016. In some severe applications with heavy nitrous, marine endurance racing, or blower usage, looser guides might be required. Check with your engine builder.

Piston Dome Clearance:

Piston dome to combustion chamber clearance MUST be checked prior to final engine assembly. This is especially important on pistons that have a .700" + dome heights which are common on high compression 427-511 based engine configurations. Pay special attention to the crest in the chamber directly across from the spark plug. Consider .040 minimum clearance with 7000 rpm or less. Slightly more would be required for motors that are turned higher.

Engine Bulder's Tip:With some domed aftermarket pistons, it may be necessary to slightly clearance or modify the piston due to our more modern (efficient) heart shaped combustion chamber design. Most of the newer manufacturer's dome profiles will clear. Note that usually less than 1cc of aluminum is removed which only equates to a weight reduction in the piston of one to two grams. If your rotating assembly is already balanced this is a non-event and creates a very slight overbalance which in theory brings your engine into a better balance at slightly higher RPMs. While some of you might be inclined to remove the material from the actual cylinder head, note that all of the combustion chamber shapes are very critical to flow and altering the cylinder head can and will effect flow and power production. The easiest way to check for this is turning the engine slowly over with the cylinder head installed without the head gasket.

Piston to Valve Clearance:

It is your responsibility to check and make sure you have adequate piston to valve clearance before final engine assembly. Don’t forget to check radial (side) clearance as well.

Spark Plug Clearance:

In the event your engine has extremely tall piston domes, it might be necessary to index the plug electrodes and/or slightly clearance your piston domes to provide a minimum of .060” from piston dome to electode tip. Do not use projected tip plugs with extremely tall dome design (unless you are certain you have enough clearance).

Note: While on the subject of clearance, it is vital that you check clearance of all moving parts due to the vast array of rocker arms, lifters, cams, springs, etc. Don’t forget to check pushrod to head clearance as well as any potential interference from your rocker arms and spring assemblies prior to final engine assembly.

Rocker Studs:

AFR BB Chevy heads require two different length rocker studs. The (8) shorter studs (referring to the coarse thread length that screws into the head) should be installed on the intake side with a small amount of Teflon or some other non-hardening thread sealer. Conventional bolt thread lubricant can be used on the longer (8) exhaust studs. Never use a shorter stud on the exhaust side.

Note: Torque Rocker Studs to 55-60 ft/lbs.

Valve Seats:

Both intake and exhaust valve seats are heat treated ductile iron and are compatible with unleaded fuels.

Guide Plates:

Only AFR guide plates will properly fit our AFR Big Block Chevy cylinder heads. We carry them in stock under AFR part #6109.

Pushrods:

All AFR cylinder heads will require pushrods that are longer than stock length. The most common lengths are a +.200” to a +.250”, however, due to a large number of variables (deck height, cam base circle, lifter height, etc.) all pushrod lengths must be physically checked to achieve proper valve train geometry. For detailed information on pushrod lenght, please view the FAQ section of our website.

Stud Girdle:

All of our BB Chevy Cylinder Heads have been designed with valve angles rolled over two degrees from stock location to provide better flow characteristics. Stud girdles produced for stock chevy castings as well as other aftermarket pieces that have standard valve angles will not fit properly. We stock a high quality girdle in a convenient two piece design that will fit our heads correctly. (Most girdles that fit Dart Heads will also fit due to their two degree roll-over design as well.)

Head Studs/Bolts:

AFR BB heads take one inch longer fasteners along the exhaust port (bottom) side of the cylinder head. AFR offers complete kits or partial kits (studs or bolts) for the eight additional longer fasteners.

Note: We recommend the use of studs due to the higher clamping load they place on the cylinder heads. Blown, turbo, or nitrous engines should always use studs due to the much higher cylinder pressures they create.

Recommended Gaskets:

Head Gaskets:Mark IV Block 4.540 Bore Felpro 1017-1

Note: 1017-2 is .051 compressed thickness

Mark IV Block 4.630 Bore Felpro 1057
Mark IV Block 4.625 Bore Felpro 1093

Note: O-ring perfectly round, .051 thick, typical “pro-stock” style gaskets.

Mark V-VI 4.540 Bore Felpro 1047 or 17048
Mark V-VI 4.630 Bore Felpro 17049

Note: All after market Merlin and Dart Big Blocks accept "Mark IV" style head gaskets.

Intake Gaskets: (For best fit) Felpro #1275
Mr Gasket #121

Note: Do Not port match your intake manifold to these manufacturer gaskets or Fel-Pro Gaskets, as they do not exactly fit AFR heads. Only use AFR’s gaskets for port matching. Most other gaskets have a slightly larger entrance. You will see NO PERFORMANCE GAIN by opening your heads or intake manifold to the larger gasket opening.

Exhaust Gasket: Felpro #1412

Spark Plug Recommendation:

(Flat seat with gasket, .750 long reach, with a 5/8 hex head)
Autolite #3932 std. tip. race application Champion #C59C Std. Tip. race application Champion #R12YC Projected tip, Street application

Note: Other spark plug manufactures offer plugs that will also cross-reference and fit our AFR BBC castings. Always consult with the manufacturer for heat range that best fits your application.

Head Bolt Torque:

All AFR BB Chevy Cylinder Heads should be torqued to 75 ft/lbs. This should be done in the proper General Motors sequence in 15lbs increments beginning at 30ft/lbs. Moly lube should be applied between fasteners, washers, and area around head bold to prevent galling and improper torque valves. Sealer should be applied to all thread areas of fasteners that enter into block water jackets. Sealer is unnecessary with blocks that have “blind holes” in the deck surface and do not go into water.

Valve Length:

Intake Valve 5.500” (+.250)
Exhaust Valve 5.450” (+.100)

Important:

Apply anti-seize to all bolts and sparkplug threads to insure long thread life.

Coolant:

It is important to maintain 50/50 mix of antifreeze in the cooling system to prevent corrosion of aluminum heads. Do not use tap water, use distilled water instead. Most supermarkets sell purified or distilled water. Check labeling to verify purified through deionization.

Head Fastener Re-Torque:

All high compression, supercharged, turbo and nitrous motors should receive a re-torque after the first running and complete cool-down. Be sure to back off the fastener about 1/8 of a turn to eliminate false readings from “break-away” torque. Always re-torque in the same general motors sequence you initially tightened them with.

Valve Lash:

Be aware that an aluminum headed/iron block combination usually requires approximately .006 tighter lash when it is cold. An all aluminum engine could be as much as .010-.020 tighter when the motor is cold. Every motor is different, but these guidelines should get you in the ballpark.

Valve Tips

Do not grind your valve tips. Some AFR cylinder heads have harden stellite tips which cannot be re-ground. If ground the tip will mushroom over causing severe damage. If your valve tips are magnetic you can grind a maximum of .015 from the tip.

Cleaning:

AFR thoroughly cleaned your cylinder heads prior to shipment. Your heads were washed in water soluble chemical agitation tank and blown out with high pressure air 3 to 4 times before they were boxed. However during some machining operations chips are packed and wedged into the water jacketing and occasionally come loose in transit. Keep in mind one chip the size of a dime breaks into hundreds of tiny chips and makes the situation appear much worse than it is in reality. It is not usually if you blow high pressure air into the water jacketing to see additional foreign debris, or chips finding their way out. AFR recommends that you thoroughly blow out your heads prior to installation.




LS1 Aluminum Cylinder Heads

    Installation Instructions

  1. ATTN: Please read through all instructions before attempting cylinder head installation.


    Springs:

    It is the customer responsibility to check and make sure that spring pressures are correct for his cam.

    Valve Guide Clearance:

    Intake and exhaust guide clearance are .00125, on some severe applications with nitrous, marine, or blower usage looser guides might be required.

    Important:

    Apply anti-seize to all bolts and spark plug threads to ensure a long thread life.

    *WARNING*

    Piston dome to cylinder head clearance must be checked prior final assemble of engine. Piston to valve also needs to be checked, pay special attention to the outside edge of the valve to the inside edge of the valve relief in the piston.


    Compression ratio and piston to valve clearances must be checked before assembly. Part numbers 1610 through 1680-1 with the 2.080 intake valve usually will not fit a piston without valve notches having proper relief’s.

    Coolant:

    It is important to maintain a 50/50 mix of antifreeze in the cooling system to prevent corrosion of aluminum heads. Do not use tap water use distilled water, most supermarkets have purified or distilled water. Check labeling to verify purified through deionization.

    Torquing:

    We suggest NOT using a torque wrench on intake and exhaust manifold bolts. Just snug up hand tight with a wrench only.

    Valve Seats:

    Both intake and exhaust valve seats are heat-treated and compatible with unleaded fuels.

    Accessories:

    Although AFR LS1 heads will accept OEM components; we highly recommend that premium aftermarket hardware be used with your new heads.

    Head Gaskets:

    Use GM#12498543 or 12498544, Fel-Pro#1041 or AFR #6830 .040 thick.

    Intake Gasket:

    Use factory o-ring style gasket or AFR #6830.

    Exhaust Gasket:

    Use GM stock replacement gasket.

    Valve Cover Gasket:

    Use factory style o-ring gasket.

    Head Bolts and Studs:

    High quality head studs or head bolts with harden washers must be used to prevent galling of the aluminum head. Recommended head bolts are ARP#134-3609, for head studs use ARP# 234-4316. For maximum head gasket clamping AFR recommends head stud kits. VERY IMPORTANT: You cannot re-use the factory LS1 head bolts. They are “torque to yield” design and can only be used once.

    Head Bolt Torque:

    Apply moly-oil mixture to washers, and area around head bolt to prevent galling and improper torque readings. 11MM ARP torque to 70 ft. lbs. with moly lube, 8mm torque to 23 ft. lbs. with moly lube. A re-torque is recommended after initial start-up and cool down (allow 2-3 hours for cooling). Sealer should be applied to all head bolts or studs that enter into the blocks water-jacketing system. Permatex is a good general-purpose sealer.

    Spark Plugs:

    Use AC 41-974 Platinum as a starting heat range. Plug selection is of course dictated by many factors including RPM levels, compression ratio, and fuel type. Forced induction or nitrous applications usually require 1 to 2 heat ranges colder. The ignition manufacturer should determine spark plug gap. You can cross reference to your favorite brand if desired. For nitrous or super charged applications a good starting point would be Auto Lite 3942, which is 2 ranges colder than stock.

    Cleaning:

    AFR thoroughly cleaned your heads prior to shipment. Your heads were washed in water soluble chemical agitation tank and blown out with high pressure air 3 to 4 times before they were boxed. However during some machining operations chips are packed and wedged into the water jacketing and occasionally come loose in transit. Keep in mind one chip the size of a dime breaks into hundreds of tiny chips and makes the situation appear much worse than it is in reality. It is not usually if you blow high pressure air into the water jacketing to see additional foreign debris, or chips finding their way out. AFR recommends that you thoroughly blow out your heads prior to installation.


Small Block Ford Aluminum Cylinder Heads

    Installation Instructions

  1. ATTN: Please read through all instructions before attempting cylinder head installation.

    Valve Springs:

    It is the customers responsibility to check and make sure that spring pressures are correct for their cam.

    Valve Guide Clearance:

    Intake and exhaust guide clearance are .00125, on some severe applications with heavy nitrous, maring or blower usage looser guides might be required.

    Important:

    Apply anti-seize to all bolts and spark plugs to ensure a long thread life.

    *WARNING*

    Piston dome to clyinder head clearance must be checked prior to final assembly of engine. Piston might need clearance with AFR heart shaped chamber.

    Important:

    Compression ratio and piston to valve clearance must be checked before assembly. Heads with 2.020 valves or larger will not fit a piston without valve notches having proper reliefs.

    Note: 1986 5.0L must have pistons notched for clearance. High flow 2.020 or larger vlave might require aftermarket pistons or notched stock pistons for valve clearance.

    Coolant:

    It is important to maintain a 50/50 mix of antifreeze in the cooling system to prevent corrosion of aluminum cylinder heads. Do not use tap water use distilled water, most supermarkets have purified or distilled water. Check labeling to verify purified though deionization.

    Torquing:

    We suggest NOT using a torque wrench on intake and exhaust manifold bolts. Just snug up hand tight with a wrench only.

    Thermo Adapters

    Thermo adapters are installed for shipping purposes only. They need to be sealed, tightened and put in their proper location; proper location is the front of the engine compartment facing the radiator. IF you are not using the air pump on part numbers 1402, 1422, 1420, 1426, 1428,1472, or 1492 you must block off the open holes on the back of the heaeds facing the firewall with 5/8-11 plug or bolt to prevent an exhaust leak. The above instructions need to be done before installing the heads on the block.

    Valve Seats:

    Both intake and exhaust valve seats are heat-treated and compatible with unleaded fuels.

    Accesories:

    Although AFR street cylinder heads will accept OEM components, rocker arms, valve covers, intake manifold, 7/16" bolts for 165cc cylinder head (except part #1396 & #1399) and 1/2" for 185cc, 195cc, 205cc & 220cc head, we highly recommend that premium quality hardware be used with your new CNC ported aluminum cylinder heads.

    Head Gaskets:

    Use Fel-Pro #1011-1 for years 1962 -1995. For high compression (12:1 and above) nitrous or forced induction, consider using Fel-Pro #1006 Locwire. NOTE: 1006 Locwire gasket will require modification of the head deck surface by a competent machine shop to Fel-Pro specifications, also put a small amount of silicone around water cross-over in head deck when using 1006 gasket.

    Pushrod Length:

    This seems like an easily answered question, however there are many variables. Block and cylinder head deck heights, head gasket thickness, varying cams, rocker arms, and valve length can all affect pushrod length. Please see our following best estimates: for 165cc, 185cc, or 195cc standard or .100 long pushrods work in most cases. For 205cc or 220cc typically .100 or .200 long pushrods will achieve proper geometry. For exact pushrod length we suggest using an adjustable pushrod to determine proper length pushrod to be used. For detailed information on pushrod lenght, please view the FAQ section of our website.

    Intake Gaskets:

    Important: Do not port match you intake manifold to these below gaskets, as they do not exactly fit AFR heads. Use AFR #6828 on the 165cc, 185cc, & 195cc intake runner head. For the 205cc use Fel-Pro #1262. The 220cc runner head will require the Fel-Pro 1262R. A small amount of silicone is recommended around the water ports and the intake port.

    Exhaust Gaksets:

    Any header or manifold designed for original equipment heads will fit the AFR 165cc, 185cc, & 195cc street cylinder heads, use Fel-Pro #1415 exhaust gasket. For the 205cc use Fel-Pro #1487 exhaust gasket.

    Valve Cover Gaskets:

    Use Fel-Pro #1645 ¼ thick cork-lam with steel core.

    Head Bolts or Studs:

    High quality head studs or head bolts with hardened washers must be used to prevent galling of the aluminum cylinder head. Recommended head bolts are ARP #154-3701 for engines with 7/16" head bolt holes (289 and 302 CI). Engines with 1/2" head bolts holes (351-w and 302 CI SVO) should use ARP # 154-3603. For maximum head gasket-clamping AFR recommends head stud kits. AFR 185cc, 195cc, 205cc, & 220cc cylinder heads come with head bolt hole drilled to 1/2". If installing on a 289-302 block with 7/16 threads, a head bolt reducer bushing 1/2 to 7/16 must be used, AFR part #6324.

    Head Bolt Torque:

    Apply moly-oil mixture to washers, and area around head bolt to prevent galling and improper torque readings. Torque to 70 ft/lbs. for 7/16" bolts or studs (289 or 302) or 100 ft/lbs. for 1/2" bolts or studs (351W) in three or four steps following the factory tightening sequence. Then tighten the long (upper) head bolts or studs to 80 ft/lbs. (7/16") or 110 ft/lbs. (1/2"). A re-torque is recommended after initial start-up and cool down (allow 2 - 3 hours for cooling). Sealer should be applied to all head bolts or studs that enter into the blocks water-jacketing system. Permatex is a good general-purpose sealer.

    Spark Plugs:

    Use 14mm x 3/4" reach gasketed spark plugs, no tapered seat plugs. Street application use Autolite 3924, for 205cc & 220cc race head use Autolite 3922, or equivalent. Plug selection is of course dictated by many factors including RPM level, compression ratio, and fuel type. Forced induction or nitrous applications usually require 1 to 2 heat ranges colder. Spark plug gap should be determined by the ignition manufacturer.

    Hydraulic Lifter Pre-Load:

    With part #'s 1400, 1402, 1420, & 1422 (stud mount) cylinder heads hydraulic lifter pre-load is easily adjustable due to the stud/guide plate design. Harden heat treated chrome moly pushrods are required with guideplate style heads. Rocker arm studs should be torqued to 60 ft./lbs. they are not torqued from AFR, torque pedestal rocker arms to stock recommendation. On part #'s 1472, and 1492 adjustments to lifter pre-load with non-adjustable pedestal bolt down rocker arms cam only be made with shims as sold by Ford SVO HM-6529-A302 or Crane #99170-1. AFR recommends 1/4 - 1/2 turn pre-load for hydraulic cams. Rocker arm geometry should be checked making sure that the contact point of the roller or pad on a stock rocker remains centered on the valve tip and does not roll off the edge. Visual inspection of the rockers, valve springs, retainers, and pushrods should be made to ensure that none of the components come into contact with each other. If problems with valve train exist, simple changes such as pushrod length may have to be made. If pushrod to cylinder head contact is evident loosen rocker stud and re-align guideplate as needed.

    Guide Plates:

    Use only the guide plates supplied by Air Flow Research! Pushrod guide plates are furnished with each set of AFR aluminum heads. Studs should be torqued to 60 ft./lbs. Silicone sealer is recommended on applications where the stud hole intersects the intake port. Pedestal mount heads do not require guide plates (AFR Part #1472 & #1492).

    Valve Tips:

    Do not grind your valve tips. Some AFR cylinder heads have harden stellite tips which cannot be re ground. If ground the tip will mushroom over causing severe damage. If your valve tips are magnetic you can grind a maximum of .015 from the tip.

    Alternator Bracket:

    Some years require the supplied 5/8-11-7/16-14 reducer to be installed into air pump thread in order to properly mount the alternator.

    Cleaning:

    AFR thoroughly cleaned your aluminum cylinder heads prior to shipment. Your heads were washed in water soluble chemical agitation tank and blown out with high pressure air 3 to 4 times before they were boxed. However during some machining operations chips are packed and wedged into the water jacketing and occasionally come loose in transit. Keep in mind one chip the size of a dime breaks into hundreds of tiny chips and makes the situation appear much worse than it is in reality. It is not usually if you blow high pressure air into the water jacketing to see additional foreign debris, or chips finding their way out. AFR recommends that you thoroughly blow out your heads prior to installation.


Air Flow Research | 28611 W. Industry Drive | Valencia, CA 91355 | 661-257-8124

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