...34/10.50-16, but I am not sure if? the tires will fit on the rim. I have a 3" body lift on the way already so I believe I will have the clearance. If that isnt going to be enough clearance please let me know, so I can get a suspension lift before I order the tires. The truck is a 1991 Chevy K-1500 4x4 350 w/ a 5 speed. Any info will be greatly appreciated, thanks....