The owners manual often does not distinguish between different options.
As Richard said fill to the fill hole on diffs, transfer cases and manual trans--doesn't matter which diff, TC or trans.
Auto trans are voodoo. When starting with a completely empty system, all seem to vary by at LEAST a half quart one way or the other even when "official" capacities are stated, and even when identically equipped. Probably depends on the temp of the fluid when checked. The GMT400's came with shallow pans, deep pans, with/without external coolers, standard size coolers and HD coolers.
Engines, again the manual doesn't discuss oil coolers and such. My 5.7's take a half pint over 5 quarts, I always put 5 1/2 quarts in when changing oil and filter. 7.4's take 7 quarts, with the external oil cooler my buddy's 1995 K2500 7.4 takes 7 1/2 quarts.
Even when I have pulled the knock sensor on my 5.7's and pulled out the radiator, the amount of coolant I put back in was less than the stated capacity--and that was with a new radiator that is almost an inch thicker than the original rad. And no, I don't have air bubbles........