Adam, you have claimed to have deadlifted 600 lbs, you even posted a pic to prove it right?
You also claim that when you dieted down, you "never lost an ounce" of muscle. If this is infact true, then you should still be able to deadlift 600 lbs, and at your current body weight of 165 lbs, thats pretty damn impressive.
Have you ever considered powerlifting?