AFR Cylinder Head Footnotes
- General special parts/requirments
- As with all aftermarket heads, a different lenght pushrod might be required.
- As with all aftermarket heads, your factory self aligning rockers might no longer provide the reliability required.
- Due to many available factory OEM style/variations your existing stud girdle may not fit.
- See below what factory OEM head AFR used for CAD/CAM modeling.
- Please see footnotes and the specific product page your researching for specific variences from OEM heads.
BBC Cylinder Heads
- Was modeled after the GM LS6 #243 aluminum cylinder head.
- AFR LS1 cylinder heads do not have provisions for 1997-1998 perimeter bolt valve covers, conversion kits available.
SBC Cylinder Heads
- Was modeled after the GM LS6 open chamber rectangle port castings.
- 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, however the middle peak or crest of the chamber directly adjacent to the spark plug (between the intake and exhaust valve) is typically the problem area in some of the older piston designs. Note that the typical amount of material needed to be removed is very small usually less than 1 cc 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 situation at slightly higher RPM. You could easily be off three times that amount by simply setting up your rotating assembly on a different shop's balancing machine. In short, don't worry about the slight removal of material effecting the balance of your rotating assembly. While some of you might be inclined to remove the material from the actual cylinder head, note that all of the combustion chambers shapes are very critical to flow and altering the cylinder head can and will effect flow and power production. We advise and recommend that you remove the material from the piston in the event you have piston dome to head interference. The easiest way to check for this is turning the engine over slowly with the cylinder head installed without the head gasket.
SBC LT-1/LT-4 Cylinder Heads
- Was modeled after the GM L-98 aluminum cylinder heads.
SBF Cylinder Heads
- Your factory accessory bolts and center bolt valve cover bolts need to be shortened 3/16" or they will bottom out.
- Was modeled after the Ford GT 5.0 cast iron cylinder head.
Air Flow Research
28611 W. Industry Drive
Valencia, CA 91355