Join Date: Sep 2000
Location: Washington, Michigan USA
Replacement sending units have varying calibrations, and generally show slightly different gauge readings than the original factory unit. Drive to a radiator shop that has an I.R. Thermo gun and have them "shoot" the thermostat housing and compare that actual reading with where the needle is on your gauge; that will tell you what the actual temperature really is, and will give you a reference spot on your gauge for where that temperature is.
'69 Z28 Fathom Green