What kind of exhaust? (if you have wet headers) Be careful of reversion with too much cam. May want to get around .222 @.050. Depending on the rise and where your water is induced. I'm sure Buiz knows better than me, But I didn't see anyone ask about exhaust.

Mike ^^^

Can anyone provide a link to the Merlin intake you guys are talking about?

Edelbrock 7561? PETO likes the air-gap 2.0 stuff

Thanks guys. I guess I am basically looking for the same performance naturaly aspirated (carb) with a 498" that I had with a whipple and fuel injection. Checkmate 270 Convincor is the hull, it ran a best of 81 mph @ 472" stock magnum heads, mild cam and CMI Sport Tube Lites and 8psi.
Hatch clearance is not an issue, I want to make the thing last and perform. I feel like I am going backwards with a carb and big cam BUT I think it is the best route.

Hey J Im concerned with running too short of a duration with my compression... however I may be ok keeping the blower cam I have with aluminum heads. This boat stuff is alot harder than race cars LOL and I'm dealin with a lot smaller window!

what chamber size on the heads you have now?

I have all new parts. 310 Dart aluminum 121cc chambers
4.070 bore 10.2 compression
4.250 stroke.

I have not bought a cam or intake/carb yet

have you thought about the crane 741 it works good on the 496 combo with good heads and intake , i have done many of these and that cam with a good single plane intake and at least a 950 and you are at 600+ hp . we did a pair using that cam and the edelbrock victor intake with a 1050 and made 640 hp at 5600rpm , they are in a 32 active thunder that runs 92 on the gps so we know the power is there.

that works out to a 448 not a 498...