It's a 472ci, all cylinders have about 9.5:1 compression.
Took out a timing light and it flashed on only 3 wires.
I took distributor apart, cleaned corroded breaker points, adjusted a screw, but it still fires on only 3 of them.
What could it be? A capacitor, wires, what else?
Take a good wire and move it to another cylinder that isnt firing, if it works, its probably the wires. But a V8 wont run on three cylinders. Get a spark tester to test the wires, they are only a couple dollars.