MuuMuu101's 68 Dart, A Learning Process...

It might work but it'll be tight. Usually I'd like to think of a finger's width (roughly 1/2" clearance) everywhere due to the tire deflection and the suspension deflection especially in the rear axle since the leaf springs will flex a little as well. This is more of an issue to the quarter panel than the spring since there won't be much dynamic movement relative to the spring.

Mine will occasionally rub pulling into my driveway where you're making a moderate left and hitting it with a good jounce at the same time because the LF fender was in an accident at one point and isn't super straight. Everywhere else it has 1/2".