And why would they make them like that?
Easy answer, They don't.
They don't event make a 55 kit rather we have mixed and matched 4x/5x/6x and 7x parts for a complete bolt-on kit exception of the rear shackle hanger. There simply isn't an OME spring that will allow the axle to be in the correct location in the wheel well without moving the perch. All other parts, shackles, bushings, shocks, etc are a direct fit.