Thanks, McDeuce -- that's great info.
I just found out the difference between my gauge's temp SENDER and the radiator's temp SENSOR ... and you're right; the sensor is a switch and wouldn't be any use to my gauge.
I'm gonna look into that adjustable thermostat, for sure.
I talked to my mechanic (installed the radiator, etc.) and he said he chose the 190/170 thermostat-switch because of my AC; you don't want the AC consensor getting too hot, he says.
He mentioned that I have a binary something-or-other and if I had a trinary thingy it would turn the fan on when the condensor got hot ... since I don't, he thought it best to run my engine a little cooler.
I said, "Doesn't a 350 sbc run best and most efficient at around 200 degrees?" He said, "No -- the newer computerized engines do, but not your setup."
I need to educate myself further on ALL these points!
54 Chevy Pickup