I've always been puzzled by rear sway bars on 4x4 vans. Unless the rig is extremely heavy it shouldn't be needed. I've removed a bunch, it seems that every DeQuig we do has a rear sway bar on it. Someone in the past thought it would tighten up the handling.
How about on a 2WD Ambo? I've wondered about a sway bar also... It's about 8500 lbs and almost 6k on the rear wheels. Handeling is decent for a 8500 lb rig. It has stock shocks, front sway, and a factory steering stabilizer... And sorry Chris no 4WD plans... That's what the 74 Fj40 is for. It's old school, but with 4 wheel discs, 33s, and a 300 hp 350, it gets the job done... And more.