If you're looking to lift your truck, one way to do it is to add a lift block underneath the rear leaf springs to gain height. This works because it's lifting the suspension vertically but doesn't affect the ride quality of the vehicle. The job involves heavy lifting and can be a bit difficult for a novice; but otherwise you can accomplish this in about an hour per side. In this case, the project vehicle is a 2002 Chevrolet Silverado, but the process is similar for other vehicles as well.
Lift up the vehicle, using the jack, and place it on jack stands. Make sure the vehicle is secure before you crawl underneath it. Remove the rear tires using the tire iron and place them to the side. Place a jack underneath the axle, and lift it up until it just contacts the center of the axle housing. Place a set of jack stands underneath the axle, but keep them at their lowest point.
Unbolt the factory U-bolts from the axle, using the 1/2-inch ratchet and socket. Lower the jack until the axle sits on the jack stands securely.
Slide the lift block on top of the axle. There is a hole in the middle of the axle pad that aligns with a pin on the block, which will keep the block and leaf spring aligned. There also is a hole on the top of the block, which aligns with a pin in the middle of the leaf spring. Use the jack to lift up the axle until it contacts the lifting blocks.
Install the longer U-bolts that come with the lift block kit over the axle and the leaf springs, then secure them down using the hardware provided with the kit and a 1/2-inch ratchet and socket.
Reinstall the tires, using the tire iron. Raise the vehicle off the jack stands, using the jack, and place the vehicle back onto the ground.
