I think you need to spend some quality time comparing the two trucks front hubs to see if there is room for the Air Brake hardware on the back of the Backing Plate on the H-C axle. I think the knuckle takes up a lot of real-estate and you may be stuck with using the Hydraulic Brakes it came with.
Normally the truck was ordered knowing it was going to be up-fitted with a 4x4 front axle by a third party vendor, so they ordered it with the correct rear axle ratio from the start to save money.
Mike B
