I own a 1987 32 ft triple e regency with a 6.2. I love it as it literally sips fuel but at 100 km/hr it’s reving at 3000 rpm. Seems to me an overdrive tranny would be a good swap. I believe these rigs have a 3 speed t400 thinking a 700r4 would be a good swap. Any thoughts. I would like to be able to do 120 on the highways