The GM factory truck parts book lists a 35 amp , 39 amp, and a 45-50 amp.The 35 amp GM part number is 1119305.Treat an old working regulator like a sore peter, don't screw with it.Poke around Ebay for a bargin regulator to use as a spare, they are around 50 bucks at the parts store.Today, probably a universal model is offered covering many AC Delco part numbers.
