What thermostat have you got in there? And have you verified that it's not stuck open? That could cause you to run a little chilly.
Gauge could also be at fault, as tooponies said.
aka "The Maybe-Not-So-Evil B$*&#"
289 v8, Powerjection III EFI, mild cam
4-speed, 3.25 9" rear
Power disc brakes, Unisteer power R&P
Pertronix ignition, RetroSound Model One radio, Classic Auto Air A/C, etc...
Three years of work for three days of perfection. This pony WILL get back out on the road and it WILL reliably take me where I want to go... and it will always, always keep me safe.