OK,
there is a sensor on the block, passenger side, between exaust and firewall. It looks like Coolant Sensor underneath alternator, but has pins sticking out. WHAT IS THAT and where can I find one. Auto Zone said they have no idea what it is.

 

Coolant sensor for the EGR system.

 

it has 2 pins (one is broken). AutoZone, Napa or ORealy don't have this kind. Check pictures. Sensor is located passed furthest injector. Plug has two identical pins. See next pic. A website where I can buy this would be realy helpful.
Again, Truck is K2500, 1993, 6,2 (J) engine

 

I know where I can get a few of them, just if the guy that has them will come off em.