[tcb-1]

crapola, I fouled that one up. I just remembered the tank that was mounted to the frame rail but that was for air-on-the-go, NOT propane.

and yes, that's block heater tubing. I had one that came out of the block in the same exact position. however mine teed off of the existing line out of the water pump. Looks like your water pump was actually modified to include a second outlet. I think it was a dealer or aftermarket install.

I simply removed the fitting on the side of the block and installed a pipe plug with a small amount of loc-tite. I'd do the same with the fitting on the top of the water pump.

or fill the radiator with desalinized water, put a tap in line on the hose from the water pump to the block and have water for your coffee......

or maybe not.