I have a Pontiac 400 American blue block and it is bored out .0060
TRW forged pistons -- I have #48 heads -- with 280H comp cam -- clevite bearings -- double roller timing chain--edlebrock intake manifold--edlebrock 750 carb--and headers.

Runs fine until I go to race it and then it detonates at the higher RPM...will not exceed 4000 RPM ...HELP!

68chick