Build thread- 73 duster, forged 5.7 w/ PS and AC, 5 spd, big brakes and floater rear
You nailed it magnumdust.
I didn't expect or plan on it. After running around for a while, there was cracking paint on the inner fender well and the underside was rubbed smooth from contact. I did a quick cut and paste right before the mile. Increased room by 1-1.5". I think I needed ~0.75" if I remember correctly.
It's probably a combination of all these things:
7.2" backspace wheels, 26.2" tire height, and the shortest bump stops I could find.