What Size Truck and Engine

Wife and I have NEVER owned an RV but are ready to pull the trigger. Nice thing is, we also don’t have a TV so we get to match our need. We are going to buy a Fifth Wheel with a dry weight between 6500-7500#. Tongue weight will be about 1400#. So, what is the smallest truck we can get WITHOUT putting any undue stress on the TV and having a SAFE pull and of course a SAFE STOP? We do plan on being in the mountains on occasion. Do not want a diesel. Have read about 2007 or newer Tundra 5.7 and Ram 1500 Hemi. We will not be buying new.

I am not sure you are going about this correctly. Instead of looking for the smallest truck that will do the job, why not look at a truck that has some reserve capacity especially if you want to upgrade the fifth in the future? The first RV is always the 'training RV' in that you learn what you want in the next RV so it becomes a progression of RV's to get to that RV that you really want. And in most cases the RV's get bigger not smaller as the progression moves into the future. Purchase the truck for the RV you will want in the future, not the one you want now.

The RV dry weight is almost meaningless, even the fifth you are looking at will weigh somewhere around 8500-9000 ready for camping and the pin weight will be 1800 or more pounds. There are not a lot of half ton trucks that will be able to handle that payload plus all the rest of the stuff, people, dogs, firewood, etc that you will want to carry in the truck.

The cowboys of old said that you cannot have too much horse; good advice for RVers as well. Donn above in his post gave you some good guidelines.