The safety and handling will be the same as a diesel. But, gasoline trucks will probably go up the mountains slower. As you probably know, you lose HP with a nonturbo vehicle at altitude. Most passes have lower speed limits than the valleys. So as long as you don’t have an issue with having a lot less HP/acceleration, you should be fine with a gasoline engine.
Fast Lane Truck on youtube does tests of hauling in Colorado for a number of vehicles. Their low weight tow tests would show you the difference between gasoline and diesels.
