Ok...I want to build this engine sort of low buck, so i figure i could re-use the factory heads. The engine is a 72-75 455 factory 4 barrel with regular (not stage 1 ) heads. Would they flow somewhat decent if i took them to a machine shop to get ported and re-done??? or do i need aftermarket pieces to get any real power?? -Rob Thanks for the help
72' heads are decent, 73'-74' are ok, if there 75'-76' toss them.(the poor chamber design will cause dettonation in a performance engine) If possible try and find some 67'-69 400,430 heads or 70'-71' 455 heads.(they have smaller cc's and flow better, if you go this route try and find big port 400,430 heads or stage 1 455 heads) Porting the heads will also make some huge power gains.(I have a mild 455 with a light port job and a little bowl work and I'm turning 464hp.)
i think it depends on your set up, if you just wanted to drag race and you get enough commpression with the heads you have, you could run a long duration cam to get the power out of lower flowing heads, but that makes for some problems, not much vacumm, high idle and need lots of gear and stall, but with good heads you can get lots of power from a mild cam, but they can cost $$$ i did my own port work on my 70 heads and it still cost about $900 to install S1 valves,hardend seats, machining for dual springs,ect... and parts
