I have a 2000 Chevy blazer with a 4.3 in it. When I tow something with it the temp gauge reads around 197 when warmed up. Then if I shut it off and start it back up the gauge will read over 200 the needle will fall back to 197 after a couple of seconds. Is this normal? It has a new radiator in it and also new head gaskets.

 

Doesn't sound out of line to me.

 

I drove it today I guess the needle hangs a little below the 210 mark when warm. The when I started it the needle was between the 210 and 260 mark. But it fell back to the 210 mark pretty quick.

 

I wouldn't worry about it unless it stays that hot

 

That is what is known as heat soak. As long as the engine is running, the water pump is providing coolant throughout the engine. When you shut the engine off, the heat is still there but no coolant is flowing. Thus, when you start it up shortly afterwards the temp guage is going to read higher initially until the coolant starts to flow and do its job.

In other words, what those said above. Nothing to worry about.