I would say that the driveshaft and related parts are rated for less than stock specifications as that is what my truck is. And I had the rear driveshaft entirly replaced as the rear u-joint went out and (as the dealer told me) the middle carrier bearing was worn badly. All at just around 30K. Don't get me wrong- I still like the truck. It is nice to have a wealth of power in an engine that will outlast a gasser, I will just have to deal with driveline wear, suspension and steering wear etc... unless I upgrade post warantee. -frank