[markandjudy86]

Has anyone had good success with a 750 CFM on a 351? Mine's a Barry Grant - Sea Demon, in my boat? I've got GT 40 heads, Edelbrock Performer manifold, Crane 214/220 roller cam, lifters and rockers, Jacobs ignition and aluminum center rise performance exhaust (thru hull with baffles). I've picked up power and responsiveness throughout the range, but warm up is very sputtery and lean. It's fine when fully warmed up and has a good warm restart without throttle. Max RPM is about 4,900. I picked up about 200 RPM over the Holley 4160 that was on there.
The question is the mixture screws need to be really different. Like 2 turns on the rt primary and 1/4 turn on the left...2 turns on the left secondary and 1/4 turn on the right. The idle's so so at 800rpm. any less and it surges and eventually stalls. Grant says I should have used the 650 CFM. Any thoughts??
(My 99 GT Conv runs great though!)

[Fordgazm]

I would think a 750 would be fine for a 351 modded . I would set the mixture screws with a vaccuum guage though . Thats the only way to do it right , without guessing .

[markandjudy86]

Which fitting do you use for the vacuum? There are a couple of small fittings at the base of the primaries. I'll neeed a gauge

No shifting, no gears. It's a boat, a heavy 21 foot cuddy cabin sterndrive. Response is excellent when I hit the throttle. It hits about 2,800 rpm immediately..kind of like a high stall converter. Currently hits approx 5,000 rpm with a light load.

[Fordgazm]

You can use any vaccuum fitting . or you can just pull it from the manifold

[markandjudy86]

It's actually a 1990 pushrod engine, although I had to change the pushrods to get the length right for the hydraulic roller lifters. The fulel distribution seems uneven and I wrote to Edelbrock. They just wrote back and asked if I had matched the ports on the manifold. I hadn't. Don't know how much dif that could make. They also said do a leakdown, although I really don't thiink I'd find anything there.

[Fordgazm]

I hate edelbrock