Im building a 454ci +.030 and was wondering what carb i should go with. When i ordered my cam Comp Cams told me use a 750 vaccumn secondary. Anyone have any opinions?

Need a lot more information.

What are you going to use the car for, primarily?
What cam, intake, and exhaust are you going to use?
What stall, rear gears?

750 cfm is going to be pretty small for a healthy 454. Vacuum secondaries will be fine if you are using the car for towing, or if you need to delay secondary opening for traction reasons.

Im using comp cams 270H magnum hydraulic roller
edelbrock air gap intake
2200-2400 stall
and was thinking 1-3/4 shortys
Was going to build everything off the motor because the car is stock at the moment & its goin to be a weekend rod

I have a 750 vac sec on mine right now. The carb seems to work fine, just have some problems getting the fuel to the carb.

At least an 800 double-pumper, or 850 VS. A dual-plane intake needs more carb than a single plane.

That cam is going to want more stall. At least 2500, 3000 would be better.

Thats what the comp cam technician told me, but i think ill go with your advice & use the 800 DP. Any other suggestion on gears etc. I really appreciate everyones input. Do you think that intake will be ok?

The intake will be fine.