Ok all you carburetor gurus time to advise my ignorance; I have a purchased motor in my challenger that the owner claimed had a carb that was not suitable. He gave me another that he had bought to put on it.

The motor: 318CID, .030 over, 9.5:1 comp, purple cam with 284/284 duration and .484/.484 lift. (and a drilled through Eddlebrock performer manf. if it makes any difference)

The original carb: A Holley double pumper ( List # 4777-5). From what i have gathered its a 650 cfm with mech. secondary.

New carb: Carter AFB Comp. series (9636). Again from what i have gathered this is a 625 cfm with vacuum secondary and designed for mopars.

So my question is should I make the swap and why? The difference in the secondarys seems to me the biggest reason to make the swap because the motor is backed with a 904.