Carb should be good. I used a edelbrock 650 first and now this 750 willys and same problem. My timing is at 14 before top dead center and was up further but it had a hard time starting that high. It does fine when you first stomp it but sputters out after its initial squirt. I will have to check in line filter, I have two of them on it one before and one after the pump. Everything is new as far as that goes. 2 brand new in line filters, new holley blue pump, and rebuilt carb. Vacuum advance isn't hooked up right now. I had the same problem hooked up and not hooked up. Not sure where would be a good place to hook to because the ports on the carb have vacuum at idle. I will have to check for vacuum leaks.