i recently bought a 89 gt with rebuilt 306. it has p heads and e cam and and most everthing else ecept stock intake. my problem is it cant get out of its own way. i had a reputable mechanic look at it and he said the compression ratio cant be anymore than 8to1 with the pistons that are in it. he also said the p heads are 64cc which makes it worse. he told he would to extensive work to them to get the compression ratio back up but i think i should just rebuild the bottom end again with the correct pistons. suggestions?
what cc are gt 40 p heads
- Thread starter schiccc
- Start date
With those heads and that compression your set up for a monster turbo or blower 
. If I remember right a buddy of mine bought some GT-40 heads that had 60cc chambers, might even be p castings for all I know complete with springs for up to .550 lift and three angle valve job for $550 or so out of a magazine. Those will bring your compression up. Get some 1.6 rollers, intake and those heads and have some fun.
. If I remember right a buddy of mine bought some GT-40 heads that had 60cc chambers, might even be p castings for all I know complete with springs for up to .550 lift and three angle valve job for $550 or so out of a magazine. Those will bring your compression up. Get some 1.6 rollers, intake and those heads and have some fun.
