Cuda versus Dart sport rims

Hello, thanks to all that can help. I have a set of centerline rims that came off of a 70 Cuda. They are fronts 15x7 235/60R15 Rear 255/60R15 15x8. To measure backspace [off-set] I measured from wheel flange to back rim bead. I come up with 4.00 inches. This is the same measurement for the front. I am told 4.00 is my backspace for my Dart. I think the tire size for the front might be to big. They are both big bolt pattern. I would just throw the wheel on but I am in Va. and the car is in Pa. Can anyone help with this?