To flip the U-bolts and simplify our rear suspension, we ordered a complete 14-bolt Simple Swap leaf spring mounting kit from Ruff Stuff Specialties (PN 14BSS). The kit comes with just about everything you need to install a 14-bolt rear axle into any leaf-sprung 4x4. It includes new U-bolts and hardware, spring plates, shock mounts and these adjustable-wheelbase, weld-on spring perches. We decided to use our existing spring perches, but we did make use of the wheelbase adjustability afforded by the kit. We drilled new centerpin holes in our perches to move the axle back 1-inch. This centered the axle under the wheelwells of our M101A3 bed a little better than before.