I have a fresh 400 with a mild cam and 4BBL. heads. The existing Holley carb is old and does not open the secondary barrels until too high of an RPM.

I am considering an Edelbrock replacement carb. Anyone have any advice for CFM or carb model. Do you think the performance series carb would be OK, I am not concerned with mileage.

Thanks.

 

As you probably already know the Pontiac 400 needs to run rich anyway. Edelbrock is a great choice, as is Demon, which I want to go to. The reason I am choosing Demon rather than edelbrock is the ease of adjustment. As far as size I have a 400 bored 30 over with a crane exciter cam. So a rather mild engine (kinda) but I have researched this and found that a 650 would be the best size. If you go too much over that you are just wasting gas for no gain... Anywaythat is what I was told. there is also a nice CFM calculator here. http://www.csgnetwork.com/cfmcalc.html if you enter the info for your engine.
Good luck