No leak found up top. Checked all hoses, heater lines, etc. I'm guessing this is a leaking freeze plug at the back of the block? Ugh! Which is easier on one of these, pull the motor or pull the transmission?

 

Its kind of a toss up. The engine will have alot of old brittle plastic clips that will break and probably some hoses that have gotten rock hard and fused with the metal tube they are on but there isnt much to pulling a 22re.
The transmission itself isnt big or heavy but crossmember on the 2wds isnt removable so you have to wrestle with it and get it at the right angle to fit and then clear the clutch and torsion bars.

 

Sure it's not a coolant leak at the EGR cooler plate at the rear face of the head???

 

Pretty sure it is not behind the head but I will look again. Maybe poke around with a scope/camera and mirror.