Hey Rusty,
I doubt that this could have anything to do with the problem but I'm running that same carb (with a manual choke) in my Jimmy and according to the documentation that came with it, those carbs aren't meant to run with too much fuel pressure from the pump. I can't remember exactly what the specs were at the moment but the max pressure seemed low compared to what you could run with a Holley. Just a thought, because you mentioned that you could feel the pressure in the line.
