Carter Question?

I am in the process of building up my 318. It is toally stock right now but a new cam has been ordered and my new edelbrock performer is waiting in the garage. I am now looking at the carb situation. Is there a big difference between the carter 650 and the edelbrock 1406? What would be some other choices? this 68 fastback still has the single exhaust so that it is my next step in the build up. then it is off to the drive train.