This chart for Chevrolet from the AC Delco electrical catalogue should get you enough information to find something. It's quite possible the GM part number will be changed up by now. If you have no luck, let me know and I can check GM when I am at work.
You can forget about the useless points and condenser and convert to electronic ignition with a PERTRONIX conversion unit. You never have to worry about ignition points and condenser again. No parts to change ever again except for the distributor cap and rotor of course. The PERTRONIX unit is the same for the 235 and 261 six cylinder engine. This conversion is as easy as two screws on the breaker plate where the points normally are mounted. Your distributor looks and stays original but inside it is modern and maintenence free except for the above mentioned parts. The PERTRONIX unit can be ordered any where in the world. I have converted all my classic cars for over 15 years now and have had no trouble at all. Easier starting, smoother running, better power and far less parts to replace. The coil can be upped to a higher output unit and the spark plug gap can be opened up to 40 to 45. It is just simply silly to keep those stupid points that pit and burn and that condenser that tends to fail. Go modern. Cheers. George.
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1957 Pontiac Pathfinder Deluxe sedan restored 261 six
1974 Chevrolet Caprice Estate wagon low mileage original 400 V-8
I know the pertronix from my 1979 VW latebay. Those old VW cars need a lot service so I ended up using the Pertronix module.
I have looked for the module but the only one I can find is for the V8 in Catalina or Star-chief. What is the Pertronix parts number?. I will need a new rotor and dist. cap anyway.
I prefer to keep the car original but the Protronix is as you note invisible.
I've always had very good luck with stock distributors but not everyone has the same luck I guess. In nearly 40 years of old cars I think I've only ever done one electronic conversion and that was done just because everyone else was doing it!
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1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars (now converted to a "factory" 4 speed)
I just checked your chart - the 59-60, 6 cylinder delco numbers shows up on parts for the corvette. The corvette had the same block. Do you know if the ignition parts was the same ?.