By hand it will only turn counter clockwise half rotation then stops ,same when clockwise stops at same point ,pulled plugs ,still locked up could it be the timing chain ?

 

If the chain failed but I've only ever heard of timing chains skipping a tooth or two so that the engine will still crank because the valves are not interfering.

Any noise from inside when you try turning it?

What you describe is like when I modified a spark plug with a threaded rod to precisely find TDC on my 289 in my Mustang. Could you have dropped a valve?

Now I'm interested too!

 

Sounds like valve interference, at 195,000 on the motor i would recommend a rebuild at this point since one way or another you're dropping an oil pan to get the timing cover off.

 

These engines are non-interference engines by design so a failed timing chain will not cause a problem such as this. Now if a valve were to drop into a cylinder either due to a failed spring or broken stem, that certainly could cause this kind of issue. A visual inspection of the valve springs by removing the valve covers should rule that out. A failed stem might not look too much different under the valve cover depending on where it broke, but it's a place to start if you don't have a borescope to look in each cylinder through the spark plug hole which is what I typically do when any obstruction type concern is suspected. A USB borescope can be picked up on Amazon for quite cheap and comes in handy for all kinds of inspection jobs!

What was the engine doing prior to this? Please provide some background on the problem.