Why won't my car start?

Okay here's what I got, 82 Cadillac coupe De ville it had a 4100 engine in it i took it out and put a 307 Oldsmobile engine in it and it worked great. Well I wanted to go bigger so i put a 350 SBC in it out of a 78 Camaro. I hooked everything up and had a problem with the distributor. It did not have a ECM plug-in so I took the module and the ECM plug-in out of the 307 distributor and put it in the 350 SBC distributor . I tried to start the engine with starter fluid and it keeps back firing from the exhaust manifold and also I do not see any fuel pumping to the carburetor (which is a quadra junk) and it is a brand new fuel pump. Not only that I used the spark plug wires from the 307 also. Somebody please tell me where did I go wrong and how can I fix this problem to get my car running, Thanks