Since its release in 2007, the JK has become wildly popular and nearly 1 million units have been sold in North America. With a wider track and longer wheelbase, the Wrangler JK is roomier, more comfortable, and delivers better on-road performance than its predecessor. However, it needs serious chassis, suspension, and drivetrain upgrades to tackle demanding off-road terrain and rock crawling. A full complement of heavy-duty suspension, chassis, steering, drivetrain, and high-performance engine parts has been developed for this platform. Co-authors Don Alexander and Quinn Thomas offer comprehensive guidance for making key modifications and selecting the best parts to transform your JK into a superior off-road performer. Lift kits from 1.75 to 5 inches are available, so you can fit off-road wheels and tires for exceptional traction. Suspension springs, specially calibrated coil-over shocks, and sway bars must work in concert to provide the correct suspension articulation and ride quality to scale obstacles and negotiate terrain. To increase durability and essential reliability, pitman arms, drop links, driveline parts, steering boxes, and skid plates are examined. Because the drivetrain must be ready for off-road service, the authors cover the most rugged and reliable axle assemblies available. Exhaust, intake, and electronic engine mapping upgrades make the Jeep 3.6- and 3.8-liter V-6 engines much more potent. It also includes how to swap GM LS and new Hemi engines into the JK for vastly improved performance. If you believe that paved roads are simply access-ways to the open range, you and your JK need this book. It contains the vital information to convert any mild-mannered street vehicle into an all-conquering off-road rig. Whether it's lift kits, wheels, tires, drivetrain, or suspension and engine parts, this volume provides detailed information, insightful guidance, and installation instructions, so you build an off-road JK to handle the toughest terrain.