[Christ]

3.55 or even a 3.73 would help tremendously.

Are your tires up to the factory spec (or higher, if you're comfortable with it.) I believe it's 35 front and 41 rear cold pressure for the LT tires you should have on there, but it could be different from my memory (Wouldn't surprise me).

You should also have LT tires on there. If you've got P-type tires, they're probably overloaded and performing poorly.

If the plow frame is attached to the front, make sure you don't still have the big-honkin' lights and such that come with it still attached. Those will cost you some funny vortices that could upset anything close to clean flow that you might have had initially.