Finally, recovery is over and Doc finally released me so I'm back working on this issue. Here's what I did.

I'm going to do a valve job at this point so I first removed the driver's side head. Tried to bar the engine over and still stuck. I removed the passenger side head and now I can bar the engine with no problem. I see nothing obvious that would have caused it to be stuck so I'm confused. Maybe I just play dumb and say it's fixed but it will bother me not knowing the reason.

 

When you turn the engine, does everything look OK on both sides? All valve opening and closing in unison?

 

Heads are off so no valve movement.

 

The Passenger (right) side of the engine is Bank 1. All references to left and right are as from sitting in the driver seat and looking forward. Left and right is NEVER seen from standing at the front bumper and looking into the engine bay.

You clearly have a problem with the Bank 1 head. Move the crank by hand and see if the any of the pistons go higher than the others, his one is hitting the top of the combustion chamber.

 

Also look at the tops of the pistons and see if there is a ding in them caused by you trying to turn the engine by hand. If you had a nut or screw that was in the way of the piston going up, it might have made a mark on the piston or the inside of the combustion chamber.

 

A piston approaches the top of its stroke the Exhaust valve will be open, making the transition to closed, and the Intake valve will be closed, making the transition to open. At the top of the compression stroke, both valves will be closed as the piston reaches the top and transitions from going up to going down. But since the valves are closed then the most possible clearance should be present. My guess is you have a valve that hangs open and the piston is hitting it. Depending on how aggressively you turned by hand, you could have a bent valve stem. I have forgotten what you were doing when you found this problem.

 

Update:
Sent the heads out for a valve job and all is well with the valves as they came back in good shape. I've cleaned off the piston crowns and they are in good shape although one has some pitting from a plug electrode that came off years ago. Once I get the head bolts I'm going to start putting everything back together. BTW, I'll be draining the oil on the off chance whatever was causing this problem made its way to the pan.

I appreciate everybody's help.

 

CLOSURE:
The truck is all put back together and I've been driving for a few days. Everything works fine, no leaks so far. I have one code I need to deal with... I broke a plastic nipple off of the EGR solenoid.

The issue of not being able to bar the engine over was irritating but maybe it was the keeper and it made it's way down to the oil pan, who knows?

Thanks again for everybody's help and advice!