I would not what Pete said. You want the nose a little high so that when you load the truck you will probably be much closer to level.
Remember you have a big tow compared to yoru little Bigfoot. Even with my 17' Bigfoot, my Avalanche really is very tolerant and even with 4 people and lots of gear I can really go smoothly down the freeway at 70+ mph.
Joe, I wasn't clear -- I meant to check the level with the tow vehicle packed and set it nose low under the actual conditions for towing, not to set it nose low with the TV empty.
BTW, everything all packed up and ready to roll as if for a trip is an excellent time to get the whole rig weighed at all axles and determine the tongue weight
. It's a bit of an iterative process because proper tongue weight and TV load will affect the hookup level, so it may take some jockeying around to get it right.
As Brian points out, an adjustable suspension (air springs, air shocks, etc.) can also be used to fine-tune the towing level.