Can you guys give me the LOW DOWN between the GM/Chevy PU & Dodge

Oh, and 8-3/4 axles were available, 60s half ton up to early ‘73, My 73 D100 came with 8-3/4 but got backed up into coastal waters too often up state and had a warranty 8-1/4 rear end installed afterward, 3.55 gears factory. Best place to find 742 or 489 HD cases. Trucks from that era had a spec sheet under the hood that showed axle models and ratio and if open or suregrip as well as engine, transmission, transfer case, springs, wheel and tire options, pretty much everything.