Hi Bill -
I just had a discussion this past week concerning this subject.
There seems to be several thoughts on the best way to do this.
Tom Langdon will suggest you take the water at the thermostat housing with his spacer with the threaded fitter in it, or use the thermostat housing from a GMC truck which has a tapped outlet on the left side. He suggests you send the water through the intake and take it around the block back to the water pump fitting using a rubber hose. Others have different ideas.
To me the shortest route is the best. I've been told it isn't because the water won't circulate unless you take it back into the system at the heater connection on the water pump. If you're not running a heater that may be OK, but if you are, then you got to rig up a "T", etc.
I suggest you take the water at the thermostat housing - on the right side, run it under the housing, over the top of the timing cover and around into the front of the intake. I then would run it out the back and, with the use of a nice brass "T" fitting, into the engine at the temperature sending unit on the head. I have been told that won't work very well, but why wouldn't it? The water pump and the water system won't know it's going in and out the manifold. It is just another route for the water to go. An argument could be made to send it out of the back of the intake and under the intake around the left front corner of the block and back in at the heater fitter on the water pump. The idea here is that it might move faster because it's being "sucked" back into the water pump. Whatever! I'm sure that will work fine. And I'm sure that a pleasing looking "T" could be made up there. It's just that spot is kind of awkward to fit a "T" into to me.
The one thing I do know, the best, and only place, to take the water to the intake is at the thermostat housing. The water is at it's hottest there just before it goes into the top of the radiator. I would return it to the system to the best place that works for your truck and engine, depending on heater requirements, etc.
The other thing I would do is run the water in stainless tubing or nickle plated copper tubing. With nickle plated copper tubing, you can use compression fittings. Metal is the only way to rest assured that you won't spring a leak because of a cracked hose.
Hope some of my ramblings help a little!
Joe
