FYI, the distributor will go in place in multiple places not just TDC on compression stroke and 180 degrees opposite. The 180 out comes into play because the timing mark will line up with the pointer at both places. So some folks who think they are at TDC on compression stroke are actually TDC on exhaust stroke.
I agree with you about the 180 degree thing. That's why I verified with valve cover off to see where in the 4-stroke cycle I was at.
Regarding the "multiple places" of dropping the distributor in, it has a flat bar (keyway) at the bottom that only allows it to drop in two ways. How could it any other?
