The 5.9L TJ: Everything’s Better With a V8

If you've ever owned a project vehicle, then you know the absolute sense of pride and accomplishment you feel once it's near completion. For Randy Crews, that blank canvas was a yellow 2001 Jeep Wrangler TJ. This would be Crews’ first Wrangler, and he wasted no time hitting the ground running. Like most, the Jeep started off with a mild lift and new tires.

However, it steadily progressed into the V8-powered trail machine you see here today. A software developer by trade, Crews would build his skillset as he turned most of the wrenches himself over the course of the build. While quick to point out that Low Range 4x4 was tremendously helpful in getting the Jeep to its current state, the fact that he was able to teach himself to weld and fabricate in such a short period of time was definitely impressive.

Having ‘wheeled in places like Moab, Utah, and across southeastern North and South Carolina, he was able to craft a build plan that would allow his Wrangler to perform on either coast. While the 5.9L may make you think of a Cummins diesel, this Dodge Durango-sourced V8 was a budget-friendly and powerful option to replace the stock inline-six engine.

We recently caught up with Crews as he enjoyed the weekend in Uwharrire National Forest located just outside of Troy, North Carolina. As is the case with most builds, this one is still a work in progress. But we were eager to share this very cool and functional Jeep. 

Sourced from a Dodge Durango, the 5.9L V8 engine is secured in place by a set of Advance Adapters engine mounts. To ensure the electronics portion of the swap wouldn’t be a nightmare, Crews had the experts at Hot Wire Auto craft a custom plug-and-play harness for the Jeep. While an electric fan keeps the engine running cool, a set of 78506 Hedman Headers attach to a custom 3-inch exhaust. 

Gone is the original Dana 30 front axle and in its place is a G2 Axle & Gear Dana 44. The swapped-in axle is housing a 4.88 gearset, Detroit Locker and chromoly axleshafts. The steering is a custom high-steer setup that uses steering knuckles from the ’99-’04 Jeep Grand Cherokee WJ. This setup offers better steering control along with better brakes.

To more effectively cope with the V8 power, the stock Dana 44 rear was served with 35-spline chromoly axleshafts and an ARB Air Locker. Splitting power to both axles is an Advance Adapters Atlas II transfer case. The gear-driven T-case has a 3.0:1 low range ratio, which offers plenty of gear reduction and wheel speed — both critical for ‘wheeling over the often muddy southeast trails. 

A Rubicon Express Long Arm upgrade works with Old Man EMU 2-inch Heavy series springs and shocks. Crews states that moving from the previous short arm suspension to the long arm setup has made a significant difference in the handling on the trail and highway.

Getting power to the ground are 37x13.50R17 Nitto Mud Grapplers. The heavy-duty extreme terrain tires are paired with a set of 17-inch AEV beadlocks, so Crews can run the single-digit air pressure figures he likes to on the trail. With two years of use on the Mud Grapplers, Crews said he’s been happy with how the tires perform. Even on rocky trails with 5 psi in the tires, he’s never experienced any problems.

One of the reasons Crews is able to run such a large tire and relatively low amount of lift is due to the GenRight highline conversion. By moving the Jeep’s flares up by approximately 3 inches, it opens up the wheelwell to allow more room for the tire to travel.

A Poison Spyder Customs winch front bumper secures an ENGO 9,000 winch and gives the TJ’s tires an unobstructed path in front of the tires. To make nighttime trail rides a bit easier, Truck-Lite LED headlights were installed along with a LED rock lights from Vision-X.

Inside, the Jeep is still a work in progress as new suspension seats and harness are next on the upgrade list. Much of the build was done at his home garage. This includes the clean 1 ¾-inch DOM ‘cage inside.

This TJ is proof that lower is better, and you don’t have to spend a fortune to have a V8 TJ. We’ve ‘wheeled with Crews for a while and have seen the progression of this Jeep firsthand. Doing his research and logging real seat time has allowed Crews to build a functional and durable Jeep that can be driven to the trailhead on Sunday and work on Monday. 

Hard Facts

See more of Crews' TJ in the gallery below and in action on video.