ok I did some searching and now Im more confused then before. Looking at holley and the demon charts I should be running a 750 or eqiv. right now I have the street avenger 770.but if i go by this equation(Cubic Inches x Max RPM, then divide by 3456 = recomended carb CFM)I should be running a 650. Iam going to be doing alot of engine work in the next 6 months.Im just wondering if a new carb should be on my list, maybe a proform or quick fuel650? The car is a daily driver but will see as much track time as possible. ok heres where im at now;

383
comp cam 08-422-8
holley SA 770 72/77, yellow 50cc cam, purple spring,47 squirter,5.5 pv
edel rpm perf air gap
100 shot of NO2
water / meth boost cooler
2500 stall w/ a.b.p.
9 bolt 345


Looking to put in
new set of dyno dons header
comp cam 08-432-8 (or solid rollercam..maybe)
possible new carb
6al msd ign
370 gear change

Any ideas, I was definatly looking to go to a dp style carb,but size is the issue.

 

I've always heard it didn't matter. . .

Anyway, the formula is the minimum size carb, and assumes a single plane intake manifold. A dual plane intake kind of splits the engine in two, and a 15% or so larger-than-formula carb typically helps the engine. That puts you in the 740 CFM range with 383 @ 5800 RPMs, so a 750 would do fine. That's what feeds my 401 cid 396 to 6200 RPMs with no complaints.

 

might have to tinker with the secondaries a little for bottom end is all

 

sweet. thanks for the info I knew there had to be something in there i was missing. Any reccomendations on carbs. I was looking at the holley dp(since i now own every tuning kit they make) or demon, quick fuel, or proform.

 

six of one and half a dozen of the other on that one dude...there is a bad one made of every brand in every price range and it's sitting on the shelf right next to the one that will work perfectly for ever...i'd buy the one i already have parts for but that's cause "if it weren't for bad luck i'd have no luck at all....gloom, despair and agony on me"

 

I hear ya.. I bought a holley dp years ago for my 55 and it was just never right, So I was soured on them. Ive ran nothing but edelbrocks from then on.My pops is running a demon on his malibu,and its amazing how dialed in that carb is. So now im trying to learn as much as i can about this style of carb.