70-71 Dart guys, Tire size ?

I'll give you what I'm running even though they're not 70 series or 14 inch rims. You can use the widths and rolling heights, though to help you (I think). On the front of my 71 I've got 15x7 cop car rallies with 235/60-15 BFG T/A's. On the rear, I've got an 8.75 with Yukon axles and stock wheel wells. Same rims as the front, but 245/60-15 BFG's. I havent yet got the backing plates on but as of now I have about 5/8" to the ss springs and about the same to the lip of the fender. They fit in there real nice. Hope this helps.