I don’t understand why the 891s are rated for more load than the 906s but not progressive like the 906s. I’m sure I’ll have a constant weight of 600 pounds in the rear. Everyone still recommending the 906s? I’m pretty much sold on the 4600s and stock springs in front but now considering 891s in the rear. Anyone have a site or link to some front springs with a 2 inch lift to somewhat match the height of the rear?