I have builds similar to what you're looking for. You don't need blowers for 600. Your basic combo with 8-71s will be 800+. I have a comp custom cam. EQ heads with no port work just bowls cleaned up and a good valve job. 8.7:1 compression. Merlin intakes. 2 1 inch spacer and quick fuel 850s. 570 on the dyno in marine trim with wet exhaust. This was through etops. With some longer runners like CMI sweepers or eickerts these would have been 600 no doubt.

Thanks Crude
what comp cam do you have?I have not heard of eq heads are they iron?

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yes they are iron. Flow very well from the box and very cost effective. It's a custom cam off their huc lobe series. 243/251 .627/.632 on a 112.

Also went with Johnson lifters. Eddie young advised on these. Ferria valves. Isky springs. Double roller timing chain.

engine quest. Most find it practical to buy new heads instead of rebuilding since it doesn’t cost much more and you get more performance. Unless you have your own rebuilding capability, free time, and are really pinching pennys rebuilding doesn’t make sense.

Crude
Did you buy them bare or assembled? Are you running stainless intake and iconel exhaust
what rpm you spinning and how much timing?Sorry for all the questions but I really like the simplicity of a single carb setup.

Bare. Had my guy go through them. Never buy assembled. Production stuff doesn't get the attention it should. I used ferrea super alloy exhaust valves. Ferrea competition stainless intake. .135 wall pushrods. Valve train is the key to longevity and reliability. 570@5900. Again. I know for a fact I'm choking myself with exhaust. Gonna be upgrading that next year and dynoing again.

Great advise and thanks for sharing it is much appreciated