It doesn't really matter where the marks are, if it runs right where you set it, then thats the right spot.
If you used a solid stopper in the spark plug hole, and slowly rotated the engine both directions, marking the balancer at each solid stop, then split the difference of the two marks, you then would have true TDC. Thats the only way to do it with the head on the engine. But in the end, its where it runs the best that counts.
Joe
