which carb would be best for me 650,670,750 all vacume sec,i will be using a air gap intake .30 hyper pistons eagle 5.7 rods and holeshot3000

There is a lot of questions to be answered before anyone can answer that with an 'informed' opinion. But my gutt says most any 327 operated below 6000rpm is going to be just FINE with a simple, little ol' 650 Holley.

No more than a tuned 1850 Holley 600cfm, vacuum secondary carb and the little motor will talk to you.

And they are very reasonably priced as is holley's old 300-36 true high-rise dual plane intake IF it will fit under your hood b/c it is like 1.25" taller than stock.

A true high-rise!

pdq67

i had a 780cfm on mine... but it was decked out with aluminum heads and all that jazz...... you could get away with a 600-650cfm carb

On my old 327 I used to run a 650 spread-bore holley Vac-Sec on a stock LT-1 (old LT-1 350/350) manifold... worked great! But for a specific reccomendation Marv is right... we need more info...