Hello Lenorg. Just made that trip last month towing my ranger on trailer with allison 3060 push button trans on a DP. there is road cons't from around Pearsonville intermittent to bishop was not to bad, as far as grades just gear down before start down don't know if you have toad brakes they would help, don't know your set up so its hard to say, there is a long straight run out after Mammoth Lakes, watch your speed at Lee Vining they watch it close (CHP), gets a little steep out of Lee Vining by Mono lake Just anticipate the grades and be in the gear you need before descent don't rely only on your mh brakes, there is a little run out berore Bridgeport and after Topaz after that your home free so to speak, I made it with no problem but I know the area well, dicression can be the better part of valor. so to remove the uncertanty and breath a little easer unhooking could be the answer. Drive ahead of the game
and have a great trip !! Ray..