I'm with C9x on this one. My '32 has P195/70R 15's on the front and P285/70R 15's on the back. I considered 17 inch rims on the rear, and I think I would like the look of those as well but I did not want to pop for the added expense. It rides and drives great. I tried bias plys on first rod, but I would never use bias ply tires on a street rod driver again. It was night and day difference in ride and handling when I switched it over to radials. If I was building a 50's style highboy that was period correct, bias plys would be on it. But I would not be driving it 400 miles to the Street Rod Nationals either. My back and butt could not take it.