In reading recent posts, I'm seeing that some rigs will do 70 on the interstate, and others will not. Mine will do 70 on flat highway, or 65 on gentle not too steep hills. Others speak (write) of difficulty going over 60 mph, or 55 mph. Mine is no hot rod - and I've been passed by a Winnie Toyota MH that was pulling a motorcycle trailer - up hill. I'm interested in what model year, tranny, and engine combos have for performance. I may trade for a different model eventually. Mine is 1984 4 cyl manual 4 speed. 72 mph on flat interstate all day. Would others mind weighing in? Thanks