Many of the older Barths have 8R19.5 tires. They are narrow and require somewhat higher tire pressures to support loads. Has anyone put 245 70 19.5 tires on a Dana 80 dually axle? I currently have 225 70 19.5 on the rear of the 85 Regal and it is time to change those tires. I would like to go to a larger diameter tire if possible.
Jim

Jim, the problem with 245R70 tires is it requires a 7" minimum wheel width. Most 8r19.5 tires are mounted on 6" wide wheels.

On a dually 6" wheel separation would not be enough and the 245R70 tires would rub together. I have 225R70 on my rears and the clearance is marginal, they work, but still very close.

Looked at both Bridgestone and Goodyear tables, and they want 6 3/4" rims on the 245s. Ed, I guess that those must not be available, ergo your comment on 7" rims. So if one wanted to put 245s on a Dana 80 axle, what would be involved? Sounds like it would not be very cost effective. Just drive at the RPMs you think your engine is comfortable with and don't worry about the speed.

6 3/4, 7 inch Wheels are available but only steel wheels. They are HEAVY! You will only gain a bit of engine life and very little MPG improvement if any.