D3 head questions
I am putting together a 521 for my jet boat. It had D3 heads on it originally, with the exhaust valves upgraded to 1.725 exhaust valves and not much else.
I realize these are probably the worst heads I could start with, but I will probably run them one year and go to alum.
The question is: Are there any substantial gains to be made by porting these? Does the Mad Porter's guide to head porting cover these heads?
Or should I just bolt a piece of chain to them and use them for an anchor?
The engine probably won't see 5000 rpm's, gonna be around 9:1 compression.
Input on rocker arm suggestions and cam suggestions (flat tappet) would also be appreciated.
I am leaning toward a Stealth intake and an 850 Holley for the intake side, it has log type wet exhaust on it.
She is a pretty heavy boat, not looking to build a racer out of it, but more power is always nice!
Thanks for the help!