So far we are impressed with the new Peninsular 6.5 diesel in the old truck. About 27 mpg (imperial) and very good power. Maybe we need a couple more tires under it though?
The cheapest fix for your load leveling problem is a pair of 4" x 6" wooden blocks. An acquaintance used to put a set between the axles and the frame on his half ton truck when hauling cement blocks.........