Freedom Fabworks Pentastar Engine Swap 1989 Jeep Wrangler

Who doesn’t want a new power plant in an old-school vehicle? For some, that means taking an old carbureted rig and updating it with a new power plant that features electronic fuel injection. For others, a built motor with huge horsepower is the ticket. Many have chosen to swap in newer LS motors or Cummins power plants. For Geoff Kubik, all of those options were considered and discarded. Instead, Geoff chose to swap in a much newer 2012 3.6-liter Pentastar engine into his 1989 Jeep YJ. Of course, along with that choice came several challenges.

Luckily, Geoff is used to challenging builds. As owner and head fabricator of Freedom Fabworks, Geoff has completed some pretty radical projects. If you haven’t heard of Freedom Fabworks, you should definitely check them out. The shop is based in Flint, Michigan and has had builds featured at the 2018 SEMA show in Las Vegas. Geoff not only loves to get out and wheel his own personal rigs, but he also loves to push boundaries and build things that others would consider impossible.

Under the hood of this 1989 Jeep Wrangler YJ is a 2012 3.6-liter Pentastar engine.

This Pentastar YJ is a perfect example of the kind of outside-the-box thinking that Geoff is known for. Geoff shared that the YJ was originally built to be used on the trails that he and his friends frequented. The previous stock motor was in perfectly fine shape at the time of removal, but Geoff just felt like it was time to do something different. “I just like to do things my way,” Geoff explained. “I want anything I build to be different. At that exact time, I was able to get that particular engine for free, so we used it”

A full custom cage and and seats make this Jeep safe for both driver and passenger.

However, Geoff also admits that if he had known the amount of time, headache, and money that would go into the build, he may have chosen a different route. “It’s not like I could go to any parts supplier and ask for a specific harness or other components. The ECM side has to be custom and getting everything to communicate properly was one of the big challenges,” he explained. Other challenges included things like the security system, acquiring special parts, and tuning to make everything happy. “No one thought we would ever get this far. We have a Jeep that starts and drives and all we need to do is get the performance tuning done now. I’m only aware of one other shop that has attempted this and in the end they gave up because they couldn’t get the motor to even start,” Geoff continued.

From a distance, this rig looks like a lot of other Jeep Wranglers. Get a little closer, though, and you'll start to notice the personal details.

In total, Geoff has about two years of work invested in the project. We asked him: with all of the challenges he knew were ahead of him, why pursue this? He explained, “We could have just done an LS-style motor swap, and literally, this thing would have been done in two weeks. A lot of people are taking out the Pentastar motors and doing Cummins motor swaps, so there are a lot of the Pentastar motors out there. The Pentastar is an aluminum motor so it is lighter, can make good power, and is about six inches shorter than a Cummins, so that moves the engine backward and improves the vehicles’ center of gravity. So there are some benefits to using them, and like I said, I just want to be different and build things that challenge me and get noticed.”

Upgraded shocks and suspension help make the Jeep a more capable and comfortable ride off-road.

We always appreciate someone that is willing to innovate and break new ground, so we definitely applaud his efforts and ingenuity. While the Pentastar motor swap is definitely the highlight of this particular rig, it is far from the only noteworthy aspect. Geoff likes to crawl in a big way, and so do the friends that he wheels with. In order to do that, one-ton axles and big rubber are standard equipment.

The Jeep is built to withstand rock crawling and whatever else Geoff and his family decide to put it through with a Dana 60 front axle and Dana 70 rear axle.

The Freedom Fabworks 1989 YJ build is no exception. With the Dana 60 front axle and Dana 70 rear axle stuffed with 4.88:1 Yukon gears, the Jeep is basically point and go. A Zip locker resides in the front axle, and the rear has been welded for some full-time spool action. 40-inch Maxxis Trepador radial tires wrapped around Hummer wheels put power to the ground, and ORI shocks up front and Bilstein shocks in the rear handle dampening duties.

A winch is a must if you plan to do the kind of rockcrawling Geoff enjoys.

The front suspension consists of a custom three-link set up and Cherokee leaf springs reside in the rear. A fully hydraulic steering system from PSC makes turning the big 40s off-road like putting a hot knife through butter. Adams driveshafts along with an NSG370 transmission and Atlas transfer case combination ensure that there is enough powertrain gearing to get the job done.

Another of the upgrades Geoff added to the rig are 40-inch Maxxis Trepador radial tires wrapped around Hummer wheels.

Inside the cab, a custom full cage keeps occupants safe in case things get a bit tipsy, and Corbeau seats with .50 Caliber Racing harnesses keep the driver and any passengers where they should be. A custom aluminum dash with a couple of personalized touches round out the interior of the Jeep. The exterior sports both half and full doors, Sinister Motorsports front high line fenders, and rear GenRight aluminum corners.

A custom aluminum dash adds a personal touch to the interior of the Jeep.

While it certainly helps to have your own fabrication shop, Geoff was quick to point out that none of his work would be possible without the continuing support from his wife and two children. Geoff is a soft-spoken guy, but when it comes to talking about his family, it was fun to see him light up. He explained that, “I couldn’t do a lot of this without my wife. She allows us to dedicate thousands of dollars to personal projects, works a full-time job, and handles most of the childcare. She is hardcore and the things she does are what allow me to work from home while doing the things that I love.” We always appreciate family focus and can certainly relate. This is one builder and family to watch out for here in the future.

With over two years of time in on this build, Geoff is eager to get it back out on the trail with his family and friends.

About the author

Christie Materni

As a photographer, and self-proclaimed "magic maker" for over 12 years, Christie loves to create anything from amazing images to great chocolate chip cookies. Traveling the country with her camera, husband, and sometimes a dog, in search of fast cars and tough trucks is her favorite way to spend the day.
Read My Articles

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