RE: Thanks guys
OK, here is my $0.02.
1. A stock M35 will work just fine with dual 11:00x20s bias ply tires in the rear. You WILL lose a little tire to bed clearance, so in extreme off road conditions you may end up with the tires rubbing the underside of the bed.
2. I doubt dual 11:00x20 radials will work, as stated above radials "squish" at the road contact surface which MAY cause the tires to contact each other, which is NOT a desireable condition.
3. Stock M35 rims are 7.5" wide, and can handle up to a 12:00x20 tire. This is stamped on the rims of my M35.
4. M135 rims have about 1" less backspace than a M35 rim (i.e., the mounting surface of the rim is 1" closer to the centerline of the tire than a M35 rim). You CANNOT single out your rears simply by using M135 rims on the rear.
5. To single out the rears, you MUST reverse the rear hubs. The front and rear hubs are the same part number, the front hubs are already flipped. By flipping the rear hubs, you then have the rim mounting surface the same distance from the centerline of the truck, both front and rear. Once you have flipped the rear hubs, it doesn't make much difference whether you use M35 or M135 rims, as long as you use the same front and rear. I would use M35 rims, as the M35 hubs are designed to center the tires between the inner and outer wheel bearings. M135 rims will move the centerline 1" outboard of the bearing centerline. Not much significance, but since you already have the M35 rims on your truck, you might as well use them. All that M135 rims will do at this point is give you about 2" wider track. Might make the singles in the rear a little more esthetically pleasing, but I wouldn't bother! With 11:00 or 12:00 singles in the rear, your tires will now be 5"-6" inboard of the outer edge of the bed, which makes the truck look a little odd. The M34 Eager Beaver was made with single 11:00x20s in the rear, but the bed was several inches narrower, so it looked "normal".
