Ditching a quick fuel carb.

So I'm having problems with my 680 ss quick fuel carb. I'ts always been rich and I guess I never got it figured out. But since I rebuild my engine and broke it in I can't get it to idle down and I can't find a vacuum leak so with it pouring fuel down the cylinders I need another one to try. I've been looking at summit and they have the 750 holly I think it's a 4150 for a little over 300 bucks with a electric choke U think this would be to big? It's going on a small block 392 stroke engine 318 based block rhs heads xe 284 cam mp ignition edlebrock airgap four speed car. I am willing to go smaller also as I'm tired of fouling plugs.