I do not see any leaks while the truck is running, and it does not pool until the truck sits overnight. I believe the engine is newer (late 80's early 90's). I can't find any wetness on any of the hoses, just a pool of coolant on sitting on the water pump towards the drivers side. If the gasket for the timing chain cover is bad, would it seep out while the truck sits, but not leak while the truck is running?

 

I had the back plate on the waterpump rust thru before.
You can't see it, until you remove the pump
#ad

 

The thermostat neck is a pain to get the gasket to sit right. That is usually what leaks for me.