Tony, I toasted a set of 5-packs in back pretty quickly due to spring wrap. As an experiment and as a way to tide me over until I could afford a traction bar, I assembled a pair of 6-packs by using all 4 leaves of 4-leaf packs, and then added 2 leaves from a pair of 5-packs.
In thinking about how to best do this to address the problems I was having (too low of a spring rate, and too much spring wrap) I figured that I needed to do 2 things: One was to increase the spring rate slightly (without going overboard) and the other was to help minimize spring wrap. Adding a long leaf would increase the spring rate, while adding a short leaf would help keep the torque coming from the axle from twisting the springs.
So what I did was added the 2nd-longest leaf from the 5-packs, and the 2nd-shortest leaf from the 5-packs to the set of 4-packs, obviously with the leaves arranged from longest to shortest. This required a new spring centering pin, which I made with a Grade 8 bolt.
I was expecting this to be a temporary fix, but it has worked out so well for about a year and a half that no longer am I munching springs, no longer is my back end too softly sprung, and no longer do I have excessive spring wrap. My problem is 100% solved, and I didn't have to spend all the money to get a traction bar. This mod is highly recommended for those whose Samurai is heavier than most (like mine) in back.
As a side note, I have had zero problems with the 5-pack springs installed up front.
-- Geoff Beasley
Suzuki Tech Editor: www.Off-Road.com