I'm may be having a senior moment because I can't see how my car is running at 50 degrees at TDC. The reading has been the same with both a standard type timing light and a Snap-on knob type light. I turn the knob to 0 on the light and the damper reads 50 @TDC, then I turn the knob to 50 on the light and the damper reads 0 @TDC.
Don at FBO has been helping me in trying to draw out this gremlin, but maybe some of you have been through this before if I remember correctly.