1974 Dart 440 tuning help

Before you do anything else, get a curve of some kind in your distributor. You're pissing away power and torque with the distributor locked out.

I wouldn't lock a street car down either, but run a MPP dizzy and see what the curve is. It might as well be locked. His car is never even under any significant driving load under 3500 RPM. If it's not detonating and it isn't pushing back on the starter, where's the issue?