The standard front axle rating was 4400 - 4500 lbs., there was an optional heavy duty axle available with a possible rating of 7000 lbs. Look up the GM Heritage Center and go to the Vehicle Information Kits, page down to the year and truck, then you can page through a lot of info on your particular model.
Wonderful, thank you so much! I think I found the correct document, as you say it does specify that the 2 ton trucks had a front axle rated at 4500lbs but since my truck is rated by GM to 18500lbs total weight I'm guessing it's a heavy duty truck and possibly equipped with the stronger axle... Gotta get down under the truck and see if I can identify what axle it has.
