temp gauge says hot

[idaford]

Just took the old 68 ford out for the first time in 3 months to see how it is doing and had a problem. I warmed it up for about 15 minutes and every thing was fine so I shut it off. About 20 min later I took it for a drive. After 5 miles I look at the gauges and everything was normal, then after another mile I notice the temp gauge is almost pegged. I pulled over and checked the engine. All seemed ok. Radiator was warm but not too hot. heater was blowing hot air and increased when driving. Had some pressure in the hoses so I released the pressure on the radiator cap and took it off, water was warm and nice and green. I let it cool down and drove the truck home crossing my fingers. The temp gauge pegged all the way over the most I have ever seen. When I got home the engine didn't seem very hot and no steam coming from anywhere.
I'm wondering if my gauge is bad or the little hose going from the pump to the intake is plugged. I replaced the thermostat last year and the radiator and engine only have 10-20 thousand miles since rebuild. Engine is a 390. Any Ideas would be much appreciated.
Thanks
Todd

[Busboy]

It aint a plugged hose. It sounds as though you have a false hot indication. The simplest repair would be to try a new temp sending unit.

[idaford]

Bought a new sending unit putting it in tomorrow.

[idaford]

Put in new temp sending unit and it seems to have fixed it.

[Busboy]

You mechanic you.