S10 bastard pack installed in a YJ
So I searched High and low looking for someone who had done the bastard pack setup in a YJ, and I found a ton of articles for S10 springs in a XJ, YJ springs in an XJ, but no one has posted anything that I could find as to if it would work for a YJ. Well, as far as success goes, it was 110%
My stock rear springs were flat when I got them, and over the last year have almost inverted from daily use and mild off roading.
I got a set of rear leafs from an early 90's (I think because the front half was missing) S10 Blazer and removed/cut the spring clamps and locating pins. I cut the spring eyes off the main S10 leaves, and cut the springs down to a length of 45". I have been prepping for my 8.8" swap for the rear end for a while, so I figured while I have the back end of the springs undone, it takes a few minutes more to undo the front bolts and do the bastard pack mod. The spring clamps on the YJ pack are pretty tough to bend out, but with a bit of persuasion from a BFH, they opened up enough for me to get the spring pack apart. I pulled the second leaf from the YJ pack out, and transplanted the cut down S10 main leaf and then reassembled the pack. Using a c-clamp to hold the leaves together, then placing the spring clamps in a vice to squeeze in the sides, holds everything tight to get a hammer in to bend back down the tabs. Comparing the old secondary leaf to the new cut S10 leaf is a huge difference. I can stand with about 25% of my weight on the YJ leaf and it hits the floor, the S10 spring however can only be bottommed out if I bounce on the leaf with my full weight. The springs went in easy as pie, and the rest of the 8.8 swap was pretty straight forward as well thanks to all the info I have gathered from this forum. I lost almost an inch of lift due to the thicker axle tubes in the 8.8 compared to the dana 35, but the overall lift from the bastard pack was impressive. I measured my rear corners before getting started and one was sagged almost an inch lower than the other, with the lower one being 23" from the ground to the corner of my tub. After the 8.8 and bastard pack, that same corner sits at almost 27" with the other corner now beng almost identical in height.
So after a quick test drive, I am very happy with my new lift. The ride is actually more smooth than it was before, probably due to me riding on the shocks more than the springs. I love the limited slip in the 8.8 compared to the Detroit I had in the d35. The disc brakes of the 8.8 also feel MUCH better than the drums ever did in the d35.
For anyone who wants a budget lift for their YJ and isn't afraid to get a bit dirty, this one looks like a winner. I will post a few updates once everything gets flexed out a few times and I have had a chance to wheel it offroad to see what they are like there.
Make sure you get a sticker that says "Jeep" in Japanese lettering, that mod is good for about 20-25 hp right there.
My Jeep has only ever killed three things. A deer, a dog, and my wallet.
*retired* Low Output Jeep Club # 135