I put the Bilstein's on before the new wheels and tires. My stock Ranchos were beat up pretty bad, so going from those to the 5100s was a huge improvement. Can't comment much on towing anything just yet. All I've had behind it so far is a 22' bay boat. Haven't gotten the horse trailer behind it yet.
With the new tires and wheels, I can't tell any differences between 275/55r20 or 33x12.5r20 riding on the bilsteins.