hi the sub-frame on the rear will be changed as well as gearbox. the reason i was looking into the map would be down to physics as 4 wheels are harder than 2 to get turning. its more a case of fine tuning the map to deliver the power efficiently with the extra load
as for buying a 4motion where would be the fun in that
Not sure you understand. It's not just the "sub-frame", its the entire uni-body platform that is different at the rear. And not just the hardened mounting points. The shock towers and bracing are all different. Chances are the exhaust, fuel tank(s), spare tire well, and truck sheet metal will be all different.