Recently acquired 1977 K20. I want an original-ish truck.

[Conly]

Recently acquired 1977 K20. I want an original-ish truck. Slowly going thru what I find to be issues. Most recent is temp gauge. Gauge works (moves off of 0 after running a few minutes) but only moves one gauge maker regardless of temp feel. I replace the temp sending unit on the head without any change. Is the factory gauge in the dash my next step?

 

[75gmck25]

Do you know what thermostat is has? Stock would be a 195 degree, but many guys get the idea that a 180 or even a 160 would work better. This is not true for a relatively stock engine. If your cooling system is bad/inadequate, changing to a lower temp thermostat willl not fix overheating.

GM changed sending units over the years, and the one you have may be wrong. Some original sending units are no longer available, so the closest I’ve found for my ‘75 is the Standard Motor Products TS6T, if you have the nailhead/ button connector. TS6 has the same characteristics, but a different connector. With that sending unit, warmed up with a 195 degree thermostat is a little lower than center scale (my gauge does not have numbers on it).

 

[Mr Clean]

 

[legopnuematic]

Welcome from Missouri.

 

[JamesSam]

Welcome from VA.

 

[animal]