OK got my new starter in, new plugs, wires, rotor, dist cap, and ignition switch, took apart and cleaned the (filthy inside) lockoff valve, fuel filter, vaporizer and carburetor. Wires were off by one on the distributor cap and the vaporizer and lockoff diaphragms were perforated, so I swapped in the identical good lockoff and regulator from the other lift after inspecting and cleaning them. I think it was running on only propane leaking by the lockoff valve diaphragm into the vacuum line before. In any case, now it starts easily, runs and revs up, but backfires thru the carb once per revolution. I double checked the firing order, ran the #1 piston to compression tdc and the distributor rotor is right where it should be. I marked then loosened the distributor and while running the engine would die if i moved the distributor either way from its original position, so I returned it to where it was.
There is a degree scale on a tab on the engine at the crank pulley BUT no mark I can see on the pulley... So I marked my #1 TDC and put a timing light on #1 plug wire and can't see my mark while running. (I need to do this again as there may have been too much background light and I need to use a paint marker as all I had that would show up was welders soapstone marker) This Prestolite distributor has no vacuum advance, has what kind of looks like a Pertronix electronic ignition module in the distributor (no black box, goes straight to the coil) and a 4 lobed magnet wheel. There is an aftermarket ignition coil marked "no external resistor required" but the system DOES have a ballast resistor. The rotor does not appear to have any rotational springiness to it that would indicate a properly functioning centrifugal advance, so I will be taking the plate with the module off tomorrow to see if something has gone wrong inside the distributor.
Along the way I rechecked compression and it was 143-149 on all 4, and confirmed the firing order of 1342 by checking that the cylinders were on compression stroke in that order. I'm hoping I find something funky inside the distributor because I'm not sure where to go after that, though I will be removing the valve cover anyway to adjust the valves so seeing that everything is moving correctly up there will be nice but I doubt there is any problem there considering the good compression. Any other ideas?