Been a while since I checked this thread, but in the meantime, I did come across some measures that might be helpful. Don't have the actual wheel-to-wheel measures, but the '46 Chevy Trucks book does indicate that the inside fender-to-inside fender width for the 1.5 ton is 87-15/16" for the dually. Centerline-to-centerline for the outside rear wheel tread is shown at 75-1/2 when 7.00x20's are used. And the front tread (again, centerline-to-centerline) is 58-1/2 with the same wheel/tire combo.
