Stock '69 318, t-quad vs q-jet vs holley vs edelbrock?

Remember that an engine is just a gas powered air pump. The whole goal is to increase flow.
4 basic parts to that.
First restriction is carb, intake manifold.
Next is cylinder head valve/port size.
Next camshaft size/lift/duration.
Next exhaust headers, exhaust pipes, mufflers.
You should also upgrade to the Factory electronic ignition system. Very simple, reliable and billions of hi-way miles proven in millions of cars.
The biggest seat of the pants improvement though are the rear gears.
A front disc brake upgrade should also be on your checklist.