carburetion question

[76sanger]

a buddy of mine is putting this together
454 +.030
approx 10.1
big brodie heads
2.25 intake
119 cc
possibly going with a 640 lift cam
he bought a tunnel ram w/ twin 600 holleys on it
question is... is this too much fuel? not enough fuel?
thanks for any info

[Blown 472]

I would think you would be better off with two 750's double pumpers, but then I am not the resident carb expert.

[76sanger]

Blown 472:
I would think you would be better off with two 750's double pumpers, but then I am not the resident carb expert. ME EITHER. thats why im asking. what cam setup would work for him also? probably gonna go mech. roller. 640 too much?

[Blown 472]

I dont think lift is as much an issue as duration, due to the rpm you want to run in, and if you have water injected headers as well.

[HalletDave]

76Sanger,
I had a friend back in the mid 1980s running an engine combination similar to what you are talking about. He tried different carb combinations and ended up with the dual 600 Holley set up on the Hi-rise. He ran it in a mid 1970 19ft Syndicate hull. He used the boat for river & lake cruising and occassionaly racing at Lake Ming. Once he had it dialed in it seemed to work fine. I have seen his time slips: 82-84 in the quarter mile @ Ming in Bakersfield, Ca. This boat was always turn key. Ask around, find out what will work best for your needs and wants. Good luck, I hope this helps.
HD

[Hotcrusader76]

Blown472 is right.
With that amount of lift on a Marine application dual 750's are almost a must. You will have a very limited top-end with dual 600's even if they were prepped by me. :D
You will have an awesome throttle response but it will be a lean one at that. Look into tuning those pump cams up to a (330 cam number 2 position) for the max shot possible and even possibly uping the squirter size 2 notches. The factory air-bleeds and emulsion circuit would then become your next handicap.
It's not one component alone that makes a carb, it's the whole system and it could take an entire day to lay out the theory of operation. Sell those carbs and look into something larger (#4779 750's for starters or even a set of #4224 660's)
~Ty