Going down the back side into Lee Vining must'a been a thrill, even with chains...that's a 10% grade if I remember correctly. Or were you coming from 395. Either way a panty buncher in the snow. Hats of Frank!
Yeah it will turn a pair of boxers into a thong real quick I learned a long time ago never to go down a hill any faster than I could climb it. I friend of mine swears by the Jake brakes in his truck I never owned a truck with them but drove several that had some form of engine brake or retarder the best thing I found them for was long straight down grades in DRY pavement. Turn em off in snow and use the lowest gears you have with a judicial application of the johnny bar all the more reason for chains on only 1 axle of the trailer. and 1 steering tire as the wife says take your time not your life. She was with me a few years back when we went over Donner Pass Climbing it at 10 to 15 MPH and descending into Nevada at 5 MPH 6 to 18" of fresh white stuff the whole way. Makes for a long ride but when you are in a 1 ton pick up and a trailer with a gross weight of 27,000 it is better than the alternative