[Overdriven]

The main issue with using a long shank pinion is increasing the load on the motor bearing. The forces aren't exactly huge, but a heavy truck with 9s and a long shank pinion is going to see more than average forces at the bearing. Regular inspection and/or replacement of the front motor bearing would be recommended. Where the setscrew is on the motor shaft doesn't make any difference in the amount of force at the bearing. Its where the gears mesh that determines the leverage and amount force placed on the bearing. The fact the pinion is an odd size is another drawback though.