Brad - back to your original question: Chevy & GMC 1/2-tons had torque-tube drive to 54, just like the cars.
On 3/4-tons the front section of drive shaft is torque-tube - to the carrier bearing - then open behind that - thru 53 at least. I'm not sure about 54 but I know by 55.1 it was open all the way. (I had one.) I wish I knew more about B-W and other OD options. .70 x 4.57 = 3.20. Not bad! I want to keep a steep low gear like my SM-420 but with OD...
