The reason I posted this is definitely about calibration. I saw someone selling a used dash gauge for a Chevy truck on Ebay that was a black face and the temp range was 220 degrees. The early GMC trucks had an electric gauge (with a temp sender that worked for both the 6v and 12v gauge as I understand) while the Chevy's stayed with the capilliary. Obviously, some GMC's also had the capilliary gauge as well). The TS-6 sender so widely sold by the repop vendors for the electric gauges does not calibrate with the early GMC (late 40's to early 50's) electric 220 degree gauge. Always reads low when the engine is hot. I'm still working on trying to find the proper sender to work with the early GMC gauge. Know what the OEM part number was but still not able to cross reference it to a proper replacement yet.
