IMO, Edelbrock carb & manifold not necessary. Stock work much better. The after market does not have much out there for Pontiac unless you go high end. I HATE electric chokes! If your having trouble starting your car this electric choke will do everything to hinder your success in starting your car! You can get these things to work for you but why bother when stocks works.

Plan to get a rebuild Quadrajet carb and stock manifold and choke.

What are the cranking amps for the battery? You said you have a new engine. How many miles on it? Mostly stock engine or have you changed the cam? New engines can be tight. I had to use the biggest (cranking amps) battery for my rebuild perf 350 HO engine. Hi duration cam made things worse.

Anyone monkey with the wiring? There is a special wire that boasts the power to the coil when starting. I believe it's a resistance wire. You can check for voltage gain when starting engine at the coil.

Vac will tell us if you have any leaks in hoses or valves, rings. You want good steady reading around 20.