A bodies in Wisconsin, Who's out there?

I'm new to the older car but have had mopars my whole life. Here is a pic of my 2 cars. The Reliant runs a 14.0 on street tires and I just got the Valiant so that is was brings me here. I live just south of Janesville. I plan moving the springs in but don't know if I want to minitub it, the trunk is so clean I would hate to cut it up. How bug of a tire can fit without moving the wheelwell?