I have a 98 Reg. cab curently lifted about 3.5-4" in the rear. I have stock leaves w/a fabtech aal that sagged and a 1.25" block. I realize i need 63" chevy 1/2 ton springs from year 88-98, and I saw that CornfedSuspension makes a front hanger so the front is taken care of but for the rear i'm confused on what they mean by double shackle. In a sense it sounds like a revolver except the factory one just chills flat against the frame, therefore moving the rear bracket back so i dont have to chop it up and weld a new one, but what shackle do i add onto the factory one to make it a double? Do i get that 2" one they have on Cornfed? is that the one i'm supposed to add to the factory one, if so how much lift will that give me. I'd really like it to sit level like it is but it seems like it's a real picky deal. Thanks guys.