The heads are based on there 225 cc intake runner head. They have been worked to a 238cc runner. The heads flow 330 cfm at .600" lift on the intake and 245 cfm on the exhaust. I will post the lift #'s throughout the lift later. The combustion chambers are 72cc. The intake valve is a 2.08" SS by REV and the exhaust is a 1.60" Inconnel piece. If anyone knows AFR's heads, they have VERY thick decks. They are about .750" thick. The retainers are Titanium and the springs are CompCams new 921 dual spring.
The bid deal with these heads for guys that don't know the LS1 world is that they are the first aftermarket head for the GEN3 motor. Up until now we have been forced to rework LS6 heads for big flow numbers. These heads where cast with improvements that we couldn't get from a stock casting.
For you guy's building GEN3 motors in the 450-600 FWHP range, the also have the 205cc head which works awesome as a bolt on power maker. The 225 head is for large displacement and/or forced induction. The big runner would hurt a stock displacement motor on the street.
Attached is a picture of the ports!
Howard
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62' Chevy 2, 427 ci twin turbo, 4L80E, Ford 9", AME 2" x 4" frame w/C5 front end......