Newbie question: how to tie down camper on the truck?

If this camper is as you described and does hang over quite a bit and also considering where you are going then I would recommend that you get Torklift frame mounted tie downs and the proper tie downs. Good luck

According to some searches for your TC I have come up with a dry weight of 3200 lbs. and if you look around inside your TC I bet you will find a mnanufacturers tag with those specs as well as capacities for LP, water, and other various info.