If I were towing that large of a fiver I would take 99 over to near Bakersfield and then 58 to 14 then on to 395. It is a longer route by a few hundred miles but it is way flatter. You need to cross the Sierras to go where you want to go. The Sierras are a very high mountain range and all the passes and the Tehachapi Pass is thousands of feet lower in elevation compared to any other route.
https://www.google.com/maps/dir/Groveland,+California/Minden,+Nevada+89423/@36.3842173,-121.5633704,6.69z/data=!4m19!4m18!1m10!1m1!1s0x8090d5ca01743961:0xcbd7390f95484aba!2m2!1d-120.2308167!2d37.8388779!3m4!1m2!1d-117.3327195!2d35.8853987!3s0x80c13020a6992d7b:0x89341d36368f8!1m5!1m1!1s0x8099bd2ff4425ff7:0x21ce2fce3bce862!2m2!1d-119.7657332!2d38.9540739!3e0