Since you're close, you might start looking for a few hundred pounds of weight savings. You won't likely find it in one item, but you could swap to some lighter stuff along the way both in the truck and trailer) and leave some unnecessary stuff home, and probably ditch 300 lbs of weight. You have to think like a backpacker or a race car builder. That 300 lbs will come off in increments of a few pounds at a time. Lighter dishes, mattresses, aluminum versus steel, fewer redundancies, etc.
Beyond that, just know that if you are in an accident and are a little over, it could cause you big issues with both the insurance companies and the law (civil or potentially criminal).
Beyond that, just know that if you are in an accident and are a little over, it could cause you big issues with both the insurance companies and the law (civil or potentially criminal).