360 runs great one day and then poorly the next

MobileCustoms said
One more thing.... Fuel pressure. What fuel pump are you running and have you verified the pressure is no higher than 6.5-7psi at most??? I had an expensive Edelbrock mechanical fuel pump guaranteed to put out only 6.5 but it was running 8+ psi. Went back to a stock mechanical $18 pump and smoothed everything right out.

I also want to add, that with my fuel pressure situation, I had the same poor (loading up) results with 2 new Holleys and a good Edelbrock carb, until I replaced the expensive pump with a stock cheapie. I could have achieved the same end results with a fuel pressure regulator, and still plan to add one of those soon.