The temp gauge has been getting up to the end of the normal mark and a little pasted lately. Im guessing it needs a thermostat? Where is it located on the 3.9 v6 dakota?

Anything else it could be? water pump, head gaskets etc. It just started to happen about 2 weeks ago. Truck has 157,000 on it now.

 

The Tstat is right where the upper rad hose meets the block, you may need to move the alternator bracket to get a straight shot at the bolts, other wise they'll go in cocked and you'll need to retap the holes

 

I still have heat, but the gauge reads right at the end of the normal mark towards hot. I was told the thermostat could be stuck? I need to know asap.

What would cause this problem

 

Yes, you could have a faulty thermostat.
But, before changing the thermostat, make sure to check your coolant level. With the engine COLD (ie, hasn't been run in a few hours) take the radiator cap off and make sure you can see fluid in the radiator. Than, make sure there is sufficent fluid in the overflow tank (should be at/near the "FULL" mark)

 

I did notice the radiator was low so i filled it about a week ago. Checked it again today some im guessing theres a leak since it was low again. Im replacing the thermostat right now and i i will check for leaks.