Engine locking up??

Curses! I took the inspection plate off, TC bolts out, turned the motor and it still locks up. I'll remove the spark plugs tomorrow. Don't believe that's the problem. I had the distributor out, but can't see how that would be the problem. I just put the manifolds on, but can't see how that would cause the problem. I know that I turned the engine before while putting in the TC bolts.

Oh Well, tomorrow's another day for a challenge.