Skip: you are correct. The motor is the only difference. Rob I am home from vacation and can send you some pictures with measurements. The biggest trick to adding electric wipers to a C-cab is the rotating disk that attaches to the wiper motor. It is the same as but smaller in diameter than a car. It has some dimples in it to allow clearance one arm to the other. I did find a disk at a swap meet and made wiper arms for the truck using the Vacuum arms and welded them to the stubs of a car arm so there were good bushings for the arm on the disk.
Posted on Feb 25, 2012, 9:34 PM from IP address 188.8.131.52