Once you get it loaded with water and gear the Cuchara is on the heavy side for a popup camper. A diesel is most probably going to run up the hills at high altitude much faster than a gasoline powered truck, but I don’t consider that has anything to do with safety.
A diesel will also get better fuel economy but the trucks payload capacity may be reduced because of the added weight of the diesel engine. Still I prefer the diesel, I owned a F-350 V8 gas truck prior to my Ram it got about half of the fuel mileage and struggled on steep hills. I ended up adding oversized anti-sway bars front and rear to my Ram and 19.5 tires to combat leaning in turns at speed. It now corners unbelievably flat at speed in mountain turns, much safer driving in my opinion.
My advice would be make sure you buy enough truck to handle the weight you intend to carry and get one with camper and towing packages installed from the factory if they were available.
