After 253,000 faithful miles the timing chain guides in the 22re have wore out. The other night on the way home I lost all heat out of the vents and the temp gauge started going up. Lucky I was about a mile from home. Got the truck home and pulled the oil fill cap off the valve cover. It had the dreaded milkshake. Pulled the spark plugs and did a compression test. Plugs were dry and looked good. Compression numbers are #1 160psi, #2 150 psi, #3 130 psi, and 150 psi on #4. This determined that the head gasket hadn't popped. The next morning I pulled the valve cover to see if there was any grooves in the timing chain cover. The pictures here show what I found.
I ordered the dual row timing chain conversion kit with metal timing chain guides and full headgasket set with toyota head bolts from LCEngineering. The dual row timing chain conversion kit comes with everything one needs to convert the single row timing chain to the dual row. It wasnt the cheapest set out there but it should make the engine out last the rest of the truck now.