We prefer to use the 4.0 in line straight six cylinder engine as apposed to the 2.5 Liter 4 cylinder. There are several upgrades for the in line 6 including:

Cool Air intake products such as:

The Trail Jammer by Edge Products
Trail Jammer performance kit is designed to provide the ideal air/fuel enhancement for your 4.0 liter Wrangler; Rubicon or Cherokee. The Trail Jammer Kit will dramatically improve the power and throttle response of your jeep both on and off the road. Included in the kit is a machined throttle body to improve drive ability, a cold air Intake to maximize air flow and electronic module (chip) to performance tune your engine. Feel the difference 20% more horsepower will make as the Trail Jammer brings your Jeep to life!

Swapping out the six or four cylinder with a V-8 is also an option. For weight to horse power, the HEMI 5.7 Liter is a good option. We use the.....

HEMI Conversion

5.7L Hemi Crate Engine - MPI, 360 Horsepower By Mopar Performance Parts

Modern technology with a touch of old school. The 5.7L Hemi® Crate Engine with custom "plug and play" technology makes installation into most Jeep applications hassle-free. It produces 360 horsepower at 5400 rpm and 360 ft. - lbs. of torque at 4200 rpm

• Built with all - new components
• Completely assembled from Throttle Body Oil Pan
• Cast Iron Cross-Bolted Cylinder Block painted Hemi Orange
• Aluminum Hemi Twin - Plug Cylinder Heads
• Distinctive Chrome Valve Covers
• Heavy-Duty Cast Crankshaft
• Hydraulic Roller Camshaft
• Cast Pistons
• Aluminum M1® Single Plane MPI Intake Manifold with Throttle Body
• Production High-Flow Exhaust Manifolds
• Roller Timing Chain and Sprockets
• Production Flex Plate
• Heavy-Duty Connecting Rods
• High-Volume Oil Pump
• NGC (Next Generation Controller)
• Custom "Plug and Play" Wiring Harnes
• Gas Pedal Mounting Bracket
• Transfer Case Mounts
• Shaft Linkage Plate
• Hemi Belly-Plate
• 33" tires are used stock axles will work fine if upgrading to bigger tires you will need to upgrade front and rear axles

Hemi Radiator

DESCRIPTION
This aluminum radiator has been designed with the highperformance Jeep owner in mind. It can be used with many of the popular Jeep engine conversions, including V6s, V8s, and the New HEMI engine. The radiator has been designed to work with many different engines by placing inlets and outlets at all four corners of the radiator. In addition it includes integrated lines for a transmission or other component cooler. The high performance nature of the radiator gives it the cooling capacity of an equivalent fivecore copper radiator, with the increased heat dissipation characteristics of aluminum.

Hemi Wiring harness

DESCRIPTION
We have specially developed this Custom wiring harness to perfectly match the HEMI engine wiring harness and the OEM Jeep wiring harness. The Wiring Harness is custom to the Make/Year/Models. Harnesses are also available for custom applications such as rock buggies that do not need the OEM dash gauges to work and will be using aftermarket gauges. The fuse/relay box will be modified from the exciting jeep wiring harness Jeep w/manual transmission Jeep w/automatic transmission universal w/manual transmission universal w/automatic transmission

Hemi TJ Motor Mounts

DESCRIPTION
Our custom designed HD motor mounts are designed specifically for TJ Wrangler HEMI engine conversions. The HD motor mount is laser cut from 1/4' thick steel and houses a pressedin rubber bushing that withstands the horsepower and torque delivered by the HEMI. The rubber bushing is designed to provide superior vibration control and also allows the engine to be placed at the proper angle for drive train compatibility. The custom weld on motor mounts provide the best solution for strength and dependability over universal bolt in mounts that have the potential to shear from the frame under high torque and high horsepower loads.

This installation will take at LEAST 4 to 5 weeks.
Crate Motor plus Installation is approximately $17,000 to 19,000
Salvaged Motor plus Installation is approximately $13,000 to 17,000

Transmission Recommended:
Automatic Transmission 545 RFE 5-Speed Overdrive is $2,000 to 3,500