Taking a Four-Cylinder TJ to V-8 Power

With the engine still on the hoist, trial-fit the drivetrain components, including the transfer case. Look for possible interference and start to think about how you could re-attach the transfer case linkage. Advance Adapters shifter linkage (PN 715542) may help if you are using the stock NV231J transfer case because it separates the transfer case shifter from the body of the Jeep.

While the wiring might seem like the toughest part of the conversion, it is not that difficult if you have both the Jeep and Dodge factory service manuals and both uncut factory wiring harnesses. Use the three plugs that plug into the computers as a starting point for comparing the Jeep and Dodge wiring harnesses. You can then splice necessary wires from the Dodge harness into plugs from the Jeep. These plugs will fit into the Jeep's power distribution center and the Dodge V-8 computer. By doing this, you can make one wiring harness that fools the Dodge computer into running with information from the Jeep's systems. The best part of all this is the Dodge computer conveniently fits in the stock Jeep location on the firewall behind the battery.

Next, the Advance Adapters V-8 TJ conversion radiator (PN 716687) was added and a stock six-cylinder TJ fan shroud was modified to fit. A '98 Jeep Grand Cherokee 5.9L fan (PN 52027888) was bolted to the engine because it fits the six-cylinder TJ fan shroud exactly and should move more than enough air for the 5.2. The upper radiator hose (Dayco PN 70480 or NAPA PN 7718) was trimmed to fit. The lower hose was made out of a stock Dodge truck hose, a metal reducer and the leftovers of the upper hose.

The Dodge power steering hoses were easily fitted to the Jeep box with a few minor modifications, and a bracket was fabricated to hold the Dodge power steering cooler. Both Dodge and Jeep used the same type of fuel fittings so the stock Dodge fuel lines were easily fitted to the Jeep chassis.

After tying up all the loose ends like heater hoses, A/C fittings, new driveshafts and any loose electrical modifications, you can focus on making the new hole for the transmission shifter in the floor. Measure for this hole three times and cut once. A shifter extension was necessary for this conversion and, with a bit of work, the stock console was reinstalled.

The evap systems, the emissions controls and the leak detection pump are secured in the TJ's engine compartment using the stock Dodge bracketry. Make sure to plumb the emissions just like the diagram found under the hood of the donor truck.