Different width rims

OK, whether its a B-body rear or A-body rear with LBP conversion and 2.5" wide brakes, you're going to need a positive offset rim, front and rear. For example. my car has the LBP 73-up disc and an a-body 8-3/4 rear with 11x2.5 drums. My car needs a 17x7 with 4.75 back spacing for the front and a 17x8 with 5.5" backspacing to fit the rear, centered. Now, as stated the 70-up cars are different, so you'll need to measure, they might be ok for your car. I'm staggering because I don't drive the car much and I like the look.