I haven't heard that...but I don't know everything.I heard a rumor that only the 8.5” rears got sway bars on the utility GMT400.
Thanks for that.The OE sway bar mounts are integral to the shock mounts. See picture of an 8.5” below.
GM uses bigger U-bolt plates to go with the bigger U-bolts, which are needed with the bigger axle tubes.The 8.5" axle tube OD is 3.125" and the 9.5" OD is 3.375" (at least on the two that I have, pictured).
Do they require different saddles to conform to the OD?