I'm thinking of trading the D/MAX for a good used 6.0 as I only pull the 5'er 10 times a summer and all short (less than 200 miles) trips. The rest of the time the rig sets or goes for short trips around town or a couple of hunting trips. Will have the snow plow on in the winter. My 5'er is a big one 12'000#. Any thoughts on this and can I upgrade the 6.0 like the D/MAX???