I hate to disagree with someone that otherwise knows his stuff, but the direction the R&P drives the wheels is determined by which side of the pinion the ring gear is on. If you invert the third, the ring gear is on the opposite side, and the same rotation at the driveshaft will now drive the wheels the opposite direction. There's no way around it, period. Picture it in your head...
If the ring gear is on the vehicle's right side of the pinion (like ours) then regardless of high or low pinion, the front driveshaft must turn CCW (seen from the t-case) in order to drive the rear of the ring gear upwards which creates a forward rotation.
Flip the ring gear to the other side, and with a CCW rotation of the driveshaft, you're now pulling the rear of the ring gear DOWN (still on the drive side of the gears mind you) which will impart a reverse drive to the front wheels.

The "cut" of the gears is determined by the pinion's orientation to the center of the ring gear. "Reverse cut" is one of the more misunderstood concepts of drivelines, often confused/interchanged with "reverse rotation" which is not the same.

I'll dig up some supporting info later, I gotta get to work...

Brent