Change everything.the starter. Flywheel. Wiring.New battery.the ground.and spark plugs.but it staring to graul like the starter and flywheel dont like the other.

Going to change 12volt.regulator and distributor.and the spark plugs wiring.to see if flywheel and starter make love.

you may have to add shims to the starter some of the older chevy's had them from the factory they go between the block and the starter also check fly wheel for cracks