02 4.6 Explorer Crank wont turn by hand

[Midnightride]

I installed new intake manifold gaskets yesterday along with new timing chain tensioners. When I removed the passenger side stock tensioner the chain jumped a few teeth but the crank and the cam gears did not move. After inspection everything looked good. I put everything back together, topped off all fluids and tried to start it up. Immediately it made a bunch of clanking noise and I shut it off after about 20-3 seconds. I thought that for some reason the timing chain completely jumped off somehow. I ripped everything back apart completely including pulling the timing chains and now the crank will not turn over by hand. It is like something is stopping it completely in the block. Both of the heads turn over by hand like they should but the crank will not move much at all. It moves about 20 degrees left and right and that's it. Any thoughts as to what might have happened? I have done the PI head swap on my Expedition with the 4.6 with no issues so not sure what could have happened other than possibly jumping timing really bad. Planning on pulling the oil pan today and seeing what it looks like. Any help would be much appreciated.

 

[Midnightride]

Well the bad news about this is that somehow the timing jumped a few teeth and I didn't spin the motor over by hand. Needless to say I am looking at a new motor now. Is the 5.4 able to drop in place of the 4.6? If so it will open up my opportunities for finding a replacement motor.