I'm assuming you are not dual cased so your dl is shorter than most people on here. Lowering your pinion will put your universal joint in more of a bind. The longer shackle will add some height, but it won't make your springs articulate any more. If your u bolts are long enough to add some more springs I think you would be happier and all you will need to buy is new center bolts. Running stock length springs (shorter) limit your ride quality and articulation more than anything. Save for hy steer for safety and run a spring set up like most people run on here (AP or RUF w/ 63") and you'll be good for a long time.