Wrong or Right Need Expert 2 cents
 

Back in 94 i built my first pontiac motor it was a 72 455 block punched .030 with trw slugs,a set of what i was told then "48" ram air iii heads (i think they were off a 350),a ram air iv intake (with holley 800 db)(i still have)and i ordered a hc-03a cam:My total combo was:455 Short block with trws,hc-03a cam,crane anti-pumpup lifters,comps 995s & 1.5 rockers switching between the 48s and a set of 7m5s.Combo kicked but,then i put 150Nos on it... Cracked block and a 7m5 head,I got another block this one is .060,i have a new a cam,i've traded my comp rockers for harland 65s and heads i got another 7m5 my question is how can i reproduce my original power with little investment?Also did i chose anything wrong in my combo?BTW the cam specs @: 244/256......504,524 @1.5 Thanks for your 2 pennys

7M5 heads? Did you happen to cc them? I remember them having short valves and HUGE combustion chambers. They would make for a really LOW compression ratio engine. I'd opt for a set of heads around 87-95cc instead, especially with that much cam.....Cliff

Elongate the pushrod holes or you will have pushrod binding. If I understand the post correctly. you have a 455 again? I would find a set of 6X-4 with that cam and needing some 9.5-1 compression heads and install a set of SS 2.11/1.77 valves.

You don't want the 455 with RA III type 72 cc senerio heads unless you plan on running race gas all the time. Over 11.5-1 compression with an iron head. Ouch.

It should fly.