Hi guys,

Currrently I have a 7.4l (330 hp) twins in my Formula 311 and see 63 mph @ 4500 rpm on a good day. At the end of the season I plan to tear them down,stud the bottom end and use a 496 stroker callies / crower crank.My question is what head / cam / carn combo will get me to 70+ staying under 5000 rpm on Bravo 1 drives. My thoughts are

Dart Heads
Holley 750,s
Bob Madera grind cam.

Thanks for your input.

you may want to find some four bolt blocks as long as your going through the effort. Sell the engines you have as assemblies since it does not appear you are using any of it anyways and put towards new blocks

How much hp does it take to move your boat at 70mph ?

Knowing this will be a great start.

i think that is the key question,,,thanks SB.........
i would guess and say u are going to need.....at least450 hp????
i am guessing....i had a 33 scarab...heavier boat ,,had crate 502's 450 hp..boat ran 64 best ever...and scarab III were not fast hulls....

as dave said ,,,u will not be using much from ur existing motors...

i am in process of what was going to be freshen up....but is ending up building almost completely new motors....

good luck........

flash......

Odds are you will find 4. Bolt blocks . Statistally speaking . Fresh or raw , gen 4 or 5,6 may dictate final displacement if you dont want to wing it too much . Sounds like a good juicy large oval canidate to me if your wanting the conservative drive saving rpm. . It will almost be like adding the power of a third motor when your done .