NGC 613
RVF VIP
If it is a Coleman Mach series AC you might look to get better flow and a little quitter unit from installing one of these. People seem to like them. A lot of good reviews. They are not cheap for what they are ,but is still a cheaper way to try and get things cooler for you. People who have installed them swear by them.
RV Airflow Systems
RV Airflow Systems