Towing a fifth wheel with a 6" lift. Will I have issues?

The 2014 303 had several complaints on the Grand Design owner's forum about not being tall enough to use with non lifted trucks. In 2015, Grand Design modified the chassis to add a two inch lift to the rig. I don't believe you'll be able to tow anywhere near level with that combination unless you either bring the truck back to a stock condition, or add substantial lift to the trailer.

Jim