Hi Big,
You can get a brand-new aluminum water outlet (the part under the thermostat) from your Chevy dealer for a '79 3/4 ton with 292 and A/C that has 3 threaded outlets in it. 2 on the drivers side and 1 on the pass. side. They aren't the cheapest, but my guess by your comment about "...where in the head should I run the temp. sensor...?" is that you don't have the hole between the #2 intake and exhaust ports. Some early heads just don't have the hole.
Actually, if you do have that hole, you could use it for the carb heat pipe instead of for the temp gauge. My experience is the water coming out of that hole is hotter due to closeness to the exhaust port, and will fool your original stock temp sender.
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David
newbie #4153
