The grape vine has a truck bypass so you should be ok, do not attempt to go up doing 75 mph, gear down you might go on 2 gear and do not place the transmission in drive and go, a transmission that keeps hunting up and down will over heat really fast, down **** at the start and maintain a steady climb, you might get down to 45mph, that is ok if you go slower turn the emergency blinkers on to indicate that you are a slow vehicle, when you crest keep the slow motion with a gear try not to use the brakes too much it is better to go slow in gear than to smoke the breaks.
navegator