I see articles about lifts for regular fleetside trucks, but not much on a dually. I dont want to go to high, because I still need to pull my gooseneck trailer. I am running 235 85 16 tires, and torsion bars cranked up, but I want a few more inches. How do I do this and still be able to use the truck?

Maybe just change the torsion bar keys so you could crank 'em up a little more (you can probably realize another 2 inches up front) and order another set of leafs for the back with some air helper springs. I would stay away from lift blocks in the rear because of potential axle wrap issues, but that's me.
The reason I say get the air helpers is because if you get a new spring pack that has a higher arch, inevitably it will have more springs in the pack (mine has twice as many as the stockers) and they will most likely be a little softer, but with the air helpers, level is just a shot of air away.

Get a Rancho 4'' lift kit.