The basic formula for building...
The basic formula for building your own spring pack is to keep your main leaf and add whatever donor leafs you choose to that. This means you don't have to build or change your stock mounts. It turns out that adding a Comanche Metric Tonne spring pack to the main Cherokee leaf yields about 5 1/2 inches of lift. We only needed about 2 1/2 inches however, so we just kept removing leafs until we had what we were looking for. Dodge Durango, S10 truck, and S10 Blazer leaf springs also work well.
We often find ourselves trying to squeeze big tires under our Jeeps without lifting them. Sometimes that leads to the reciprocating saw and sometimes that leads to the junkyard. Over the years, we've honed our skills to the point that we have some very definite opinions on how to get a bit more lift for many Jeep models using junkyard parts.
A good rule of thumb is to go up to the next weight classification. For example, most of our Jeeps are basically 1/4-ton animals so we tend to look at 1/2-ton vehicles for lift options. Usually swapping the springs from a 1/2-ton SUV or truck into a lighter Jeep will yield some lift.
For coil-sprung rigs, the overall diameter of the spring and diameter of the top and bottom of the coils is important. For leaf-sprung rigs, the width and length of the individual leafs is what to look at. However, you can always cut the length to suit, so that is less critical. Once you find leaf packs that have the same width as the leaf packs under your rig, pay attention to how much arch they have with the weight of the vehicle on them, as well as how thick the individual leafs are. Typically, when swapping leafs around, thinner and flatter leafs will yield a better ride both on- and off-road.
We could go on for days about what works and what doesn't, but this isn't Junkyard Swap Magazine, so we'll cover some of the highlights here. If you like pinching pennies until they scream, this will get you going down the road to a cheap and readily available way to lift your Jeep.
On the coil side of the equation,...
On the coil side of the equation, springs from a V-8 equipped Grand Cherokee ('93-'98) will give about 1-inch of lift to a six-cylinder-equipped TJ, XJ, MJ, or ZJ. If your MJ or XJ has 2WD springs in it you can expect more like 2-3 inches of lift. Likewise, using six-cylinder springs in a four-banger will yield about 1-inch of lift while the V-8 springs will be just north of 2 inches. Of course, all these measurements depend on how beat your stock springs are, how much of a porker your Jeep is, and the condition of the donor springs.
If you are looking for more...
If you are looking for more lift than that, you can start looking at 1/2-ton trucks and SUVs. Make sure the coil diameter is correct. Shown are two TJ front coil springs. Note how the top (right) has a smaller diameter than the bottom (left). We once used coils off an early 80's Ford truck and got about 4 1/2 inches of lift. We ran it for a while, but it rode horribly. We've yet to find a coil that will give more than 2 inches of lift without compromising the ride.
Whatever leaf springs you...
Whatever leaf springs you end up using, look for springs that have friction pads. There are two types, the type where the pad is adhered to the spring, and this type where the pad pokes through the spring with a locating tab. This is our preferred style. Using the friction pads greatly reduces the friction between leafs and provides for a better ride and increased flex over a pack that doesn't have the pads.
We like to use the main leaf...
We like to use the main leaf from the front of a six-cylinder YJ to augment our stock YJ leaf packs. We use the six-cylinder main leaf because it has a higher spring rate than the four-cylinder leaf. Simply cut the eyes off the main leaf right where it starts curving and add it to your pack for 1-2 inches of lift and added antiwrap protection. Shown here is an exploded view of a YJ pack with the added leaf. For a slightly-stiffer ride but with 2-3 inches of lift, front '80s-era Wagoneer springs work well. However, if you use the entire pack, it will move your axle about 2 inches due to the offset centerpin.
Speaking of centerpins, if...
Speaking of centerpins, if you are taking your leaf springs apart, get new ones. You can find new centerpins online, but finding them locally is often difficult. The old pins are usually rusted and just not safe for use. Also, since you are adding leafs, you will need a longer centerpin anyway. In a pinch, a decent hardware store will have grade 8 fine thread cap head bolts (top). Some light grinding on the head of the bolt until it tightly fits the spring perch hole may be needed.
This is our final answer for...
This is our final answer for our Cherokee leaf pack, which yields about 2 1/2 inches of lift. From top to bottom are: stock XJ main leaf, second leaf from MJ Metric Tonne, third leaf from MJ Metric Tonne, early '80s Toyota truck overload leaf, XJ fourth leaf. We basically mixed and matched until we had the ride we wanted. Make sure that no individual leaf is too much shorter than the next one in the pack, or it will be more likely to bend when wheeling. The Toyota leaf came in when we had to haul two axles and a transmission in this XJ. Because it is perfectly flat, there was minimal impact on unloaded ride and ride height. We did lose some flex (uptravel) off-road, but not enough to worry about.