A quick check on Cooling system

So when my truck warms up it'll get about 3/4's the way up on the temp gauge then it'll go back down (quite fast if i'm above idle) to below 1/2. so is this normal or possibly a sign of thermostat starting to give? and where is the thermostat located on the 2200 (carbed)?

looking at the motor from the front of the truck. its on the left side were the upper rad hose connects to the motor. as for the needle mine does the same thing. the going up to 3/4 is when the thermostat is closed. Then when it goes down thats when it opens up allowing water to flow. My owners manual says that halfway is the norm for a 92 b2200 carbed

cool, thanks!

def. sounds like thermostat... what a bitch those things are..... if you've never changed it.... then... more then likely its a few years old... a thermostat goes through alot of abuse and should be changed ever other winter (or at least thats what i was taught at the radiator shop i worked at for 3 yrs... )