lazy temp gauge

[jks67ss396]

Guys

I have a 71 with temp gauge (not sure if some just came with lights, but i have the gauge)

Anyway, i seem to have a lazy temp gauge. meaning that it just starts moving when the temp is 180 ish.

This gauge always kinda did this and i thought maybe temp sensor. Well, i just completed my 5.3 4l60 swap and i have a temp sensor in the head from a 98 Camaro (works with the pcm and has a port for a gauge). So watching hptuners, I can calibrate the temp in the pcm with the temp on the gauge.

I did ground the sensor wire and the gauge did peg full hot. So i believe the wiring is correct.

Maybe the 5.3 doesnt flow coolant till the tstat opens?

So do any of you other guys have a gauge that always reads low?

thanks!