Basically any 15" rim ever made will fit a 275/60 behind a 73 plymouth B body. I run 275/60/15 on mine with a 15x7 rim with 4.25" backspacing and there is a mountain of room on each side. These cars have a ton of room in the rear wheel wells. Later this year I want to go to a 15x10 rim, custom backspacing and a 28x12R15 tire(biggest I can squeeze with stock leaf spring location) or 325/50 tire if I want to do a leaf spring relocation.