A friend of my just got into Mopars after being a GM guy for years like me. He bought a 70 Grand coupe, and would like to go with 17x9 rear wheels with a 5.5 back space. I said I'm not sure if they will fit without relocating the leaf springs. I went with 17x8's with 4.5 back space and they fit. He did not say tire size, but I'm thinking it will be 245/40/17's.
Thanks for the help.