[BossHogg69]

I'm not on 20's, but my truck is lowered roughly 4.5" (spindles/springs) up front and 7.5" in back (6" spring, 1.5" block), but the big block adds a little more weight up front, so it's really closer to 5" (actual measurements, not guessing). I started out with a 2.5" spindle and 3" CPP drop spring, but I dragged the arms a couple times, so I went with stiffer Hotchkis 2" spring that's 1400#/inch and they keep everything high and tight .

What tire sizes are you wanting to run? My tires are 26.5" up front and 27" in the rear as they sit on the truck. Just something else to consider. Then you have to decide if you're going to run inner fenders, and then backspace of the wheels to make sure it all clears, and the list goes on...