Ok, looking to lift my 71 k-5, 4" Susp. questions. (1) What brand is best equiped, best ride, do they all have the bushings between the leafs for the ride. (2) with 4" susp. lift do you really have to mod. drive lines. (3) stock springs right now so do you think a shackle flip kit for back would work. Don't what blocks in back. Thank's for any help.