[Driver Ed]

It would be very useful to me for someone to explain in some detail their theory for what went wrong.

Here's my theory:
It seems to me that what happened is the because the IMS bearing on is on the transmission side of the engine (as is the 1-3 chain), and that because when I replaced the IMS bearing I needed to move that end of the IMS about 1/2 cm toward the 4-6 side, that the problem is likely to be on the 1-3 side and not the 4-6 side, which has its chain on the other end of the engine. When I moved the 1-3 end of the IMS back in position, I suspect that I inadvertently retarded the valves on the 1-3 side and that the exhaust valves on that side are what is now impeding the engine's movement. If there's a flaw in that theory, or a plausible alternative explanation, please enlighten me.