So you guys are saying it's possible that, when the left-most crankshaft timing mark and both camshaft marks are lined up, I'm not actually at TDC, aka top of compression stroke on cylinder #1? So all the marks are wrong? That seems even less likely than the distributor flipping itself. I can shine a light in the spark plug hole to confirm piston travel, but I'd have to pull the valve cover to confirm the valves are closed for the compression stroke.