Has anyone used the 800cfm marine holly on a 330hp 454 with any luck? I know you guys told me to use the 750 cfm but teauge swears by th 800 and they do this everyday.

Can be done but not necessary. Especially on a stock engine or any 454 turning less than 5400. Ive tried and still prefer the 750. Better starts, acceleration and fuel mileage. There are those using them succesfully. Better for a 502 IMHO.

For that type of Power A 750 is going to be a much better choice.

Ditto on what they said.

i am going to use one this year, not by choice it came with the heads and intake as a pakage deal. i would rather have the 750 but i will give it a try.

454 (ci) x 5400 (max RPM) = 2451600 / 3456 = 709.375 cfm

Just my .02

Dave

Remind me guys, which is it? I think you can get away with a larger carb on a dual plane intake, right?

A dual plane intake can help crutch using a carburetor that is too big, but remember that carburetors work based on air velocity. If a carburetor is too large for the application there won't be enough air velocity, and it will run lean at WOT. If Boob sold you the carb, he may already have some pistons put aside for you. You're going to be better off with the 750 carburetor, regardless you're not going to get the 5 MPH gain you want without going into the engine.

Thats very true, when I tried the 800, I had to jet the heck out of it.