I have a 88 s4 vert and the temp gauge would run just about 1/4 and after doing a pull a snapped a belt and it got hot about half way and i shut it off i put the new belt on and now it runs just a little below half.Why is it running hotter then normal and should i be worried running it for long at that temp

 

Maybe the belt is slipping on the water pump and is in need of adjustment?

 

Did you lose coolant?
Have you checked coolant level?
Have you check the overflow tank...is it at the indicated "full" level?
Is this the stock gauge? ...and if so, is it linear?
Is it the same ambient temperature as when the belt broke?

 

yes the coolant is full it is the stock gauge and when the belt broke it got a little over half the hottest ive ever had it but now normal temp is a little below the middle it used to be at 1/4 before the belt broke

 

As long as it is not over heating or eating or losing coolant I would not be concerned about it.
Just make sure your belt is properly tensioned.

That stock gauge tells you exactly NOTHING about how hot the engine is so Personally I would seek out an aftermarket gauge and install it.