WaterTemp

[siii8873]

My truck is back running after swapping engines. I put my 69IIa engine in my 74 SIII. One difference I see is that the water temp is low. It does not get any warmer than the top of the white cold mark on gauge (85 deg and sunny out). Not a big issue now but will hamper heat when it gets cold out. Original engine ran about 1/3 way up on gauge.
My thought is thermostat. One question before I change this is there a difference between the sending units of the two engines? Checked the connection and that looks good, same wiring harness ect.

[jac04]

I would check the temp sender & gauge combo against a known temperature like boiling water. See what it reads. Running only 1/3 of the way up on the gauge still sounds a little low, so maybe there is something wrong with the gauge itself. Just a thought.

[siii8873]

I cando this test but I don't know where it should read on the gauge.
The gauge is more of an indicator with genera ltemp info, C,N,H cold,normal,hot. Where would 212 DegF (boiling water) be in this range?

[jac04]

I would think that it should be getting toward the top of the "N" range.