How to Hemi Swap a Jeep JKU

Emir has a philosophy that when something on his vehicle breaks or needs to be replaced, he puts something bigger and better in. And when the original engine started knocking in his 2008 Jeep Rubicon, that's when the fun began.

The engine swap started with a donor vehicle, a 2008 Chrysler Aspen and a long night wrenching with a good friend to free the 5.7 liter v8 Hemi from its former bay. It was ready to embark on its next adventure living in Moose (that's the 2008 Jeep JKU).

Watch a video about it here: Everything you need to know about Hemi-swapping a Jeep JK

The adventure continued with removing the ticking engine, installing some engine mounts from Jeep Speed Shop (JSS), and replacing all the seals in the donor engine and transmission.

Over the course of two weeks on weekends and evenings, Emir commandeered his friend's garage to complete the swap. He kept some parts from the original engine like the power steering reservoir and alternator but had to modify some things like the steering column, battery box, and A/C lines. Of course, there were some hurdles like finding out that the new engine would touch the frame of the vehicle meaning that Emir had to install a lift kit.

And then there's the wiring. Although the Jeep and Chrysler have similar systems, there were a few wires to find and connect so the new engine would talk to the rest of the Jeep's wiring. But after printing about 40 pages of wiring diagrams, Emir began splicing and connecting, merging and locating the two vehicles into one. There was one small hick-up with a green and gray being joined to something instead of a gray and green, but otherwise it was relatively smooth sailing.

After flashing the PCM, installing the lift kit, and building a simple transmission mount, Moose was ready to roll. It roared all the way to the shop where it then got an exhaust system fashioned to the new engine and we eagerly waited to test it out.

The first test was trying its power at a mud bog. Aside from some heating concerns, the Hemi swapped jeep was working, powerful, and so, so muddy (we are still finding mud and it's been almost two years since the mud bog races).

Of course, Emir learned a few things along the way. First, the stock Jeep Gladiator radiator is way better than even a nice aftermarket one. The jeep needs a fan shroud (made of something more durable than cardboard). He did end up getting a longer drive shaft for the front as well, but the rear is still stock even with the lift due to the new transmission set-up. And otherwise, Moose is perfect... well almost. With the added power, new brakes were also needed but that's a story for another day!

If this looks like a modification you'd like to see to your jeep or you want to nerd out about engines and wires, and how the cruise control still works, or even how your wife steals your jeep because it has so much power now, feel free to reach out! Get in touch and let's do some more cool swaps.