The manufacturer says these tires should go on 6.5-8.5" wheels. Ya think they'd be OK on 6" since they have a lot of sidewall? I've put 285/40s on rims that should only have 275, so if those were OK with the short sidewalls, the 255/70 should be OK on 6"???

The whole story is that I'm buying 7" cop car rims for the car, but in order to get it home from the buyer, I need to put tires on it when I get there to pick it up. It has the original biasplys on it from 1973 :)

First, I would use the 30 year old tires under only one circumstance - static display. DO NOT RUN ON THEM!!!

For TEMPORARY usage, you could get away with it, but get the proper sized rim ASAP!

Hope this helps.

You would need at least a 6.5" to seal on the bead of the rim. That's what that rim width means. If it's beyond that range the sidewall will be pulled in so far that the angle of the bead on the tire will not fully seat/seal.

Listen to Grant, he is the man when it comes to Rims and Tires.