Originally Posted by HaxbySpeed (Post 4242520)

Yessir, 9.8 to 1, 89 octane, similar sized cam to what you're running, maybe a hair smaller. 2000cfm throttle body, Holley efi intake. It was a low rpm deal, made 770hp. I built a 600" with AFR 305's last year. I wouldn't try to argue with anyone that those are the right heads for a 600" motor, but it worked really well for it's application, and the throttle response was nothing short of violent. It made 705hp and 740 tq through a set of Dana's. I do a lot of engines for big white water jet boats that have a very narrow efficient rpm range so I experiment a lot with different combos. When the pump manufacturers are designing new impellers, they use a shaft dyno to calculate the KW absorption of the impeller. My dyno numbers always match the numbers in the boat. The 357's are a killer head, and a perfect match for a 598 if, in my opinion, you were shooting for 850-900hp. I was just saying that on an engine that mild, I couldn't see spending the money on them. I'd go with cheaper heads and buy shaft rockers instead. :)

https://youtube.com/watch?v=I1XC7qqFY9E