1972 Dodge dart custom 4 dr trying to beef up.

I agree with Red66GT that zac_F71's recipe is the wrong one. What's really needed before any parts shopping or swapping is at least a day spent carefully planning out exactly what the car needs to do differently than it does now, and a time-and-money budget for the work. Don't forget, cars that go faster also need to stop and steer faster/better, too.