255 60 15

[55mike]

Yes.. 58" is about what works without moving springs etc...

[chevynut]

FWIW..... I'm running 255/60/15 on 8" wheels. The backspace is 3.5", and the 9" F^&d is 58" wide at the wheel mounting surface (vs 60"). It's a very tight fit. 55's fenders by their design tend to be a bit tougher to deal with in these situations. I have to remove the lower shock mounts, pull down on the rear shackles and the tires still drag on the inner fender edge to get in/out. Once in, they look good and don't rub..

Your wheels have 1" negative offset so a 58" rear puts the center of the tires at 60", about the same as stock. The 10" tire would be about 70" outside and 50" inside. Most of these cars have 71.5-72" between wheelwell lips. The tubs are 46.5" and springs are 48" outside so you should have about 1" between tires and springs. You could actually go with a 275 tire if you could get it inside the wheelwell. As long as you can get wheels with the right offset you can go with just about any reasonable rearend width, if you can center the tire in the wheelwell. I've had guys asking me what rearend width to use and I tell them to choose a wheel and tire first.

[55mike]

Your wheels have 1" negative offset so a 58" rear puts the center of the tires at 60", about the same as stock. The 10" tire would be about 70" outside and 50" inside. Most of these cars have 71.5-72" between wheelwell lips. The tubs are 46.5" and springs are 48" outside so you should have about 1" between tires and springs. You could actually go with a 275 tire if you could get it inside the wheelwell. As long as you can get wheels with the right offset you can go with just about any reasonable rearend width, if you can center the tire in the wheelwell. I've had guys asking me what rearend width to use and I tell them to choose a wheel and tire first.

I've seen 275's on 56's/57's but the fender opening on my 55 (bottom edge) distance to the brake drum is super tight. Perhaps if I dropped a shackle and got the rear down a bunch more 275's could be squezzed in. As I stated before, the 255's are really hard to get off/on (helps to unbolt the lower shock and torque the shackles downwards).

[asbicca]

If you move the springs under the frame, a 15 x 8 wheel with a 3 3/4" back space, and a 58" mounting surface to mounting surface rear end you can fit 295 50R 15 BFG T/A's. In order to mount or dismount the wheel and tire you need to undo the shock and any traction bars and deflate the tire. Then a bottle jack between the bottom of the frame arch and the top of the rear axle tub and the wheel and tire fall right off.
This is the best picture that I could find, but it is doable.