Your trucks looking good man. I would suggest changing some of your shackle angles and lengths. Something is limting your trucks flex in back- my guess is your tire is hitting the inner fender well on compression limiting the droop you are getting on the opposite side. It's hard to tell in the pic but your front shackle looks like it's at about the stock angle. If that's the case, move it up and see how that helps. While your flex is good, I think you could get another foot off the ground with some tweaking. When I first finished up with my truck it flexed horribly. With the right spring and shackle location/lengths nearly perfected, it's now putting down 1300 plus on a 20* ramp.