pjv911

I agree with you guys. So yeah staying with the 7.4 and using the forged internals I already have makes the most sense.
As of now it appears the 731 cam profile is the right choice. If there was a profile one step lower I think it would make even more sense. Using the factory rollers and pushrods would be another bonus.
Not sure if my stock rollers are up to the abuse the 731 cam will have. Gunna need to match my springs to the cam too.

phragle

iTrader: (3)

Im usin a 721 in the 454 Im building. I went with different lifters,,,it wasnt worth the gamble, These are what Im using (Walmart buddy, only the best for my blower motors)

https://www.walmart.com/ip/Crane-Cla...2-16/112440378

pjv911

From what I've learned based on the stampings on my RHS heads they are 119cc chambers. 320cc intake runners.
.030 over 454 and 9.5:1 compression
high rise dual plane intake
750cfm carb
gil manifolds/risers through the prop
Will I make 425-450hp with the 721 cam?
or will I need to go the 731 route?
or neither will get me that power?
also looking for a roller rocker suggestion.

phragle

iTrader: (3)

measure your valves, and have the cam specs, there are a bunch around here with desktop dynos that are pretty accurate with good information.

pjv911

2.25 intake 1.88 exhaust. As for the the cam? That's the part in question.

Unlimited jd

iTrader: (5)

I'd have to look at the cam card to see overlap to check how it would be with your exhaust, but would make 420+ without a problem with your heads and 9.5:1

pjv911

Thanks man.

Scott Danforth

I agree, used forged internals if your going to beat it. also have the rotating assembly balanced. I also recommend SFI rated damper and flywheel. mainly because I have witnessed first hand when cast flywheel comes loose and goes thru the hull of a boat.

pjv911

If anyone can check HP on desktop dyno for me that what be very much appreciated. Please use the 731 cam.
Here is a link for cam specs. http://www.cranecams.com/140-143.pdf
Curious to see how the 721 cam would do as well but don't want to ask too much.

phragle

iTrader: (3)

You will have better luck if you start a new thread title "can someone run a desktop dyno on my combo?' Thats much more likely to catch someones eye that can do it.