I had a distributor push itself up far enough to disengage itself from the gear on the cam shaft. I had failed to push it all of the way down when I installed it. The distributor gear caught just enough of the cam gear to run, but that did not last very many miles. You might want to look into that possibility before you move on to checking the timing gears.

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission