More on Delco distributor

Look, most of these distributors are over 50 years old. Most people don't even know they have a lube oil reservior in them so they never add oil to the reservior and the bushing/shaft wears and the dwell gets erratic and the engine runs like a three legged dog. They put in new points and it still runs bad so they rebuild the carb and the engine still runs bad so they replace the carb and it still runs bad, etc.... they never bother to check the spark because by now they have replaced the points, condensor, rotor, cap, and wires so the spark must be good. Yeah, right!
And this happens with all these old distributors whether they are Delco or not. They just plum wear out. You can get'em good as new by either going through them yourself or having a place that knows distributors do it for you. There are some special tools that maybe required to do the job correctly and you have to have access to the correct parts. In my case, the shaft was worn as well as the bushing. Either they put it on a lathe and turned it down and then made a custom bushing to fit. Or they had a spare shaft that was in better shape and they made the bushing to fit that shaft. These guys secialized in old distributors and mine came back like new.