Dana/Spicer Corp. builds final drive axles. Their Type 44 axle is a 1/2 ton rated axle that also fits a few passenger cars, the Type 60 is used in heavy-duty 1/2 ton and/or 3/4 ton trucks, and the Type 70 is used in dual-wheel applications for 1 ton and some heavier-capacity vehicles. Good axles, and they're used by several manufacturers, Foed, Chrysler, GM, and International, to name a few.
Jerry