Bob:
The distributor is secure. Timing hasn't changed since it was running good. The movement I refer to is the small vacuum advance amount. The only thing I've done is file the points (while in the distributor) & change the spark plugs. All this was after the ruff, chugging idle started.
I think I'll pull all my plugs & the valve cover & hand turn the motor to see if I have a stuck valve.
