Well, thanks to 2plus2's help, I'll be putting in 4.56 gears (I won't go higher, thanks to his tip about abs brakes and speeedometer concerns).
In searching the web for my ring and pinion purchase I've learned there are three sizes, those being 9.5 inch, 10.5 inch and 11.5 inch. How do I determine which of those three is in my truck's rear axle?
Also, how do I determine which ring and pinion to purchase for the front differential?
I have a 2005 Silverado 2500HD 4x4 crew cab (4 door) with the 8.1 liter engine and the Allison transmission.
Answers to both questions would be greatly appreciated.
P.S., I called the dealership where I bought the truck and was told they can't tell me which ring and pinion size is in the rear or front differentials, and that they must be visualized to know for certain.