Carl, the diameter of all 4 tires is 26.66 inches. Please know that the picture of tire-in-fender well is with the truck on a lift, so rear end is suspended in air.
My dirveshaft (when I finally order it) will have a slip yoke which gives maybe a 1/4 inch room for error on specifying the length of the drive shaft... that is really all that I have been obsessing aboout (this time around). I would like to have the wheelbase as close to 116" as is practical, and after measuring a number of different ways back when I assembled the chassis, I think it is whithin 1/8" of 116.
If I was to stop measuring and start ordering, I would specify driveshaft length to be 54 1/8 inches.
