which motor you have in yours and what year is it?I own one of these, it’s been a blast, it goes anywhere. The lack of power only is an issue on long mountain passes or once you climb above 8,500 ft of elevation. Other than that I can cruise at 70 mph at get about 24 mpg at my home elevation of 5,000 ft. Gas mileage improves the closer you are to sea level too. If you want more space get a hitch installed and have storeage off the back.
I am looking at 1992 Hi ACE camper with a 2L naturally aspirated (non-turbo) 4 cylinder.