Sorry to disagree Captain, but I don't want others to be mislead. A dial indicator will not show true top dead center. It will show when the piston reaches it's highest point, but that is not true top dead center by a number of degrees. How much depends on rod/stroke ratio, etc. but the point is, it is not true top dead center.

After the piston reaches it's highest point, the crankshaft will rotate several degrees before the piston starts back down. That's called it's dwell time, and that's why you can't simply use a dial indicator to find TDC.

AV8TOR