I wondered why my big A body rad in my G body could not cool my 260 in my 88. For one I didn't turn the rad cap on, why not, more coolant on the ground, sure why not. I turned on the fans at 230, down to 215 with the fans on when I noticed the rad cap. Shoot my temp gun at the sender and thermostat housing, nothing above 170 WTF? It read 10 degrees high, now 45 high, ridiculous! Anyone see cheap gauges like this Sunpro be so far off?