50-state legal 2007-2011 JK jeep engine swap guide

Are you ready to perform the ultimate modification – a Hemi Jeep conversion? If so, the following instructions will help you get the job done right.

Step-by-step JK V8 swap guide

Great news! You do not need to remove your Jeep’s body to install the JK Hemi kit. Leave the body on the frame and follow these steps to complete the job successfully.

Stock engine and transmission removal

  1. Take your Jeep to a repair facility to have the AC system evacuated.
  2. Relieve fuel system pressure as outlined in the factory repair information.  
  3. Disconnect the negative battery cable.
  4. Remove the air intake and air filter housing.
  5. Remove the battery box and disconnect the plugs going to the grille.
  6. Take off the underbody splash shield and drain the coolant.
  7. Remove the grille and unplug the marker lights.
  8. Disconnect the oil cooler lines.
  9. Remove the heater hoses, coolant reservoir hose, as well as the upper and lower radiator hoses.
  10. Disconnect the following electrical connectors: alternator, throttle body, knock sensor, TP sensor, IAC, O2 sensor, CMP, purge solenoid, MAP and engine wiring harness.
  11. Detach the wiring harness from its retainer and move it out of the way.
  12. Disconnect the PCV hose, EVAP hose and EGR tube.
  13. Disconnect the fuel lines going to the rail.
  14. Disconnect the electrical connector and refrigerant lines from the A/C compressor. Cover the openings so dirt and moisture do not enter the system.
  15. Raise and support the vehicle.
  16. Disconnect the OPS and O2 sensors.
  17. Remove the CKP sensor.
  18. Disconnect the optional block heater on vehicles so equipped.
  19. Disconnect the starter electrical connectors and remove the starter.
  20. Unbolt the exhaust pipes from the manifolds; remove the entire exhaust system.
  21. Disconnect all electrical connectors, tubes and linkages from the transfer case.  
  22. Remove the transfer case and drivelines.
  23. Disconnect all electrical connectors, lines, tubes and linkages from the transmission.  
  24. Connect the engine to a hoist (cherry picker) chain for support. Putting the chain through both exhaust manifolds works well.
  25. Double check that everything is disconnected from the engine and transmission.
  26. Unbolt the engine mounts and transmission mounts.
  27. Remove the engine and transmission together as an assembly.

Don’t forget to keep the battery cables, ground wires and EVAP line for reuse. In fact, it’s a good idea to keep all the old parts until after your Jeep JK engine swap is complete.  Also, you will need the old PCM for a core.

Hemi engine installation

  1. Cut the stock engine mounts out using a plasma cutter or a die grinder.


Alternately, Jeep Speed Shop’s bolt in engine mounts can be used.


  1. Lock the steering wheel with the wheels pointed straight ahead. Then, secure the steering wheel so it doesn’t turn and damage the clocks spring. There are various ways to hold the wheel; securing it with bungee cords often works.
  2. Remove the lower intermediate shaft.
  3. Remove the upper intermediate shaft.
  4. Grind about 3/16” off the firewall welds to move the pillow bearing to the left (toward the booster).
  5. Install the locating bracket for the new mounts in the frame. Then, line up the new mounts with the oval holes in the frame and pull them forward to meet the locating bracket. Weld the bracket into place.


Note: when installing a truck Hemi, you will need to use the lower holes in the engine mount. If you are using an LX-style car engine, you will need to use the upper holes in the mount.

  1. Remove the reservoir from the power steering pump.
  2. Use the kit-supplied parts to modify the stock power steering pump for reuse.



  1. Modify the stock AC compressor by drilling a hole to countersink and Allen head bolt.  


  1. Modify the oil filter adapter so that the Hemi filter will fit; weld a nut on the threaded bung, then remove the bung.
  2. Bolt the new exhaust manifolds to the engine.
  3. Install wiring harness.
  4. Lower the engine and transmission together into the engine bay.
  5. Bolt the engine and transmission to the mounts (the OEM trans mounts are reused)

If you’re using a non-VVT Hemi engine, you will also need to do the following:

  1. Modify the fan shroud by cutting out the stock electric fan and replacing it with a mechanical fan.


  1. Create a fuel line adapter that takes the 5/16 line to 3/8 line.
  2. Reroute the wiring that went under the battery box to go over the box.

That’s it! You’ve just completed you Hemi Jeep conversion. Now, it’s time to take pride in your work by showing off you’re one-of-a-kind ride.