my 99 durango heater gets warm but never gets hot and thats only on the the lower 2 blower settings when on high the air is cold that comes out my temp gauge never moves once the suv heats up stays around 150-180 range "thats a guess as theres no #'s between 130 and 210" ive heard alot about the suv needing a 195 thermostat to blow hot? unsure thats the issue

 

Check heater hoses. Hot in but not return, its a clogged core. Flush it.

 

Had a similar issue with the Ram I used to own, had crud in the heater core.. Definitely would try flushing it, also make sure that there is not air trapped in it. The thermostat is supposed to be a 195 btw

 

I had the same issue. I flushed mine using hot water in a 5 gallon bucket with a little radiator flush in it. I hooked up a little pump on an electric drill and circulated the water from the bucket through until a bunch of crap came out. This will require getting extra hose to run from your heater lines to the bucket.