Power in Your Jeep JK
DIY Engine Conversion Kits



400HP / 425LB-FT

485HP / 475 LB-FT

Get the BOM

The swap will take many Mopar parts to complete. Review the corresponding Build – Of – Materials below

Research the Process

No two builds are the same. JSS will support you during the build but it is your responsibility to research how your build will go together.

Start Wrenching


Massive horsepower and torque in a street-legal, emissions-compliant engine built with OEM Chrysler parts. You didn’t think it was possible, but you’re going to love your Jeep even more.

If you want Hemi power under the hood of your JK, our DIY conversion kits are your easiest and best solution.

Our shop has been perfecting the art of Hemi conversion kits for Jeeps since 2004. We’ve pioneered with innovations and smart features to bring you powerful, reliable, and easy-to-install conversion kits that fit any JK.

Get everything you need for a DIY engine swap and enjoy turning your JK into a Hemi-powered beast. We’re the only shop building Hemi kits that pass California emissions — so if you want to get on the road with a truck motor in your JK, this is your chance.

The only Hemi conversion kits that are Emissions compliant are the Truck Hemi kits, ( Jeeps 1997-2011) (except the 2006 Jeep TJ/LJ) Our kits are CARB Legal, we are going the extra mile to make our kit stand out and to be the best engine conversion shop.

Jeep JK V8 swap: why a Hemi is better than an LS engine

Which is better: Chevy or Mopar? That long-lived debate is hard to settle unless you’re talking about Jeep engine swaps – then the answer is undoubtedly Mopar. While LS engines are great, there’s no substitute for a powerful Hemi engine in a Chrysler Corporation product, like the Jeep Wrangler JK.

Don’t get us wrong; we love LS engines. In fact, we produced a Chevy conversion for many years. But there’s one major problem with the Wrangler LS swap: it isn’t smog-legal. At least not in California and other states with similar emissions laws. Plus, getting a Chevy V8 to work in a Chrysler product is troublesome, to say the least.

Why choose Hemi conversion kits from the Jeep Speed Shop?

Get your conversion kit from the shop that professionals turn to for ensuring emissions-compliant V8 engine swaps. When you install a Jeep Speed Shop kit in your JK, you get a perfect fit and the best performance possible. All in an OEM equipment package and customized for your JK.

We build the best Hemi conversion kits, and you get the best value for your money.

New, top-of-the-line parts

We use 100% NEW parts, including mostly OEM Chrysler parts

Production line engine and transmission

New from Chrysler

Emissions compliant in all states

Our kits meet the strict California emissions standards

Made in the USA parts

From the radiator that handles all weather to the engine-driven cooling fan built right in our shop

Custom programmed Hemi computer

Specially designed just for the JK

OEM Performance and style

A custom wire harness for any Hemi engine swap.

One thing to keep in mind when swamping out your 6 cylinder engine and keeping your Jeep all Mopar, you can now take your Jeep to the Jeep dealer for any Warranty work and recall work, if you change the make of the engine most Jeep dealers will not do any WARRANTY WORK OR RECALL WORK do to the Jeep being modified with a NON-CHRYSLER ENGINE. Example. like if you need to replace the TPIM or the ABS module you will need the dealer to reflash the Jeep so you can get the new part to work, we have found many dealers do not want to work on a NON-JEEP OR CHRYSLER PART. Our Hemi conversions can be serviced at a Jeep dealer, this is why we are working on CARB APPROVAL FOR ALL OF OUR KITS.

Laura Hodgson

Positive: Professionalism
Excellent service and communication – highly recommended if you want to put a Hemi V8 in your Wrangler. Todd and his crew were able to fix issues from another shop that did my original Hemi conversion which failed emission testing in CO. For over a year the original shop was not able to get my Jeep to pass emissions. Todd is the expert on CARB certified and emission compliant Hemi engine conversions. I now have a completely legal and beautiful Hemi JK. If you are going to put a Hemi engine in your Jeep, you should do it with Jeep Speed Shop as it will be done right and will be legal and pass emission testing the first time. It was well worth the drive from CO to CA. Thank you, Todd!

benjamin j

Positive: Professionalism, Quality, Value
Hats off to Todd what a fantastic job he did on my 07 Jeep JKU! I went with the 5.7 VVT Hemi truck engine with 8 speed transmission and it was one of the best decisions I ever made. I just got my rig back last week the sound of the V8, the smoothness of the 8 speed with manual sifter and all the powers I’m gained makes my Jeep become one of the bests around. It’s also 100% Carb legal, which is a big deal for me since I’m from Cali. The customer service was outstanding and the communication was great! Todd’s been sending me the WIP pictures during the entire process. He even posted a video on YouTube and IG to show off my 8 speed. All in all, I’m beyond happy and so glad that I went with JSS for this project! Again, thank you Todd and Liz for everything you’ve done and I just hope your shop is closer to me! :)

Michael Egli

Absolutely amazing. If you look back at older reviews you’ll see they went through a slump. Some bad staff left a few customers unhappy, but all of that has changed after management went through the business and wiped the slate clean. Now, they are once again the best engine swap experts for Jeeps HANDS DOWN.
In my case, the most recent project was a 2008 Jeep Wrangler Rubicon (not much left of the Rubicon though). 6.4 SRT Hemi Swap, Auto, Atlas 4 Speed. They not only tackled that with beautiful precision and an absolutely factory look, but they also took care of a half dozen other issues such as cleaning up some wiring from the previous owner, fixing ebrake issues, and much more.
Their communication has been stellar. Their professionalism amazing. And the quality of work is beyond words. If you are looking for an engine swap, do not pass Go, do not collect $200, call these guys ASAP and do whatever you can to let Todd do this for you.