DPelletier:
If you're still curious about the weight rating try inspecting the inside of the wheel after you remove the cracked wheel and dismount the tire. I think the weight rating will be molded or stamped somewhere on the inside of the wheel. I've seen that on other wheels.
As others have said, the rating will be approximately one fourth of the GVWR for your truck or a minimum of approximately 2500-3000# per wheel. Dodge and other manufacturers don't make the wheels. An aftermarket supplier like Hayes-Lemmerz, Accuride, or other manufacture the wheels and sell them to Dodge and other truck makers.
Harvey