Another SBC won't start story. Purchased a McKinnon 283 (chevy) that was removed from a '65 Studebaker and rebuilt, I purchased it fall of '19. I installed it in my '55 Stude Speedster. Once installed and hooked up it started and ran. After sorting the usual idle adjustments I timed it. During winter of 19-20 I routinely started it to run a bit. As winter wore on it got harder to start. Eventually, I could only start it with starter fluid but once started it ran. As winter entered to spring it would not start even with starter fluid. I tried a few ordinary things/ I drained the gas and replaced it with fresh premium fuel. The carb has been professionally rebuilt and I have good fuel pressure and it squirts gas when pedal depressed. On a warm day I tried to start it and fiddled with the choke and idle screws. Eventually I was able to get it running after pumping the gas and keeping the choke closed, even after a fire started in the carb from too much fuel in the intake. After it ran a bit, and warmed up, it would start, with some difficulty, and run. Once it cooled off it would not start again. So I had already previously installed new ignition wires. The distributor came with the engine and is an aftermarket with a Petronix unit. I then replaced the coil, no affect, replaced Pertronix ignitor module, no luck, checked the distributor ground, cleaned contacts, no result. Then I noticed that the rotor contact plates were loose, a ha, I'got it. Nope. The only thing I have not replaced is the distributor cap, but it looks fine! Oh, and I have 12 volts from the ignition switch to the distributor. I have a ballast resistor, but the feed to the distributor is before the resistor. Suggestions?