Installation Instructions

Small Block Ford Aluminum Cylinder Heads

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.

*WARNING*

Rocker studs are installed for shipping purposes only! These studs must be sealed and toruqed to 60ft/lbs before running the engine. Pedestal toruqed to 25-30lbs.

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.

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 & 205cc & 225cc 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 and 185cc standard or .100 long pushrods work in most cases. For 205cc or 225cc 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 Fel-Pro #1250 on either the 165cc or 185cc intake runner head. For the 205cc use Fel-Pro #1262. The 225cc 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 or 185cc 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 part #1420, #1422, #1450, #1451, and #1492 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 & 225cc 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.

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.