What's the best way to break my rig while towing?

350lbs of tongue weight where it all goes on the rear axle, or 350lbs in the cab, where 1/2 goes on the front axle...

Just put your **** in the cab and hit the road.

Some will argue that there's absolutely no way to set up a 2500 "right" for as much weight as you're carrying, but what's done is done.