Lexus IS300 3UZ Swap Part 2 Pulling the 2JZ and Picking Up the V8

Part 2 of the Lexus IS300 3UZ swap is officially underway. This is where the build takes a major step forward. The factory 2JZ comes out, the engine bay becomes a blank canvas, and we pick up the 3UZ FE V8 that will completely transform this car.

This swap is about more than just horsepower. It is about torque, sound, driving feel, and building something different within the Toyota and Lexus world.

If you missed the teardown process, you can read Part 1 of our Lexus IS300 3UZ swap build series where we removed the radiator support and wiring harness.

Removing the 2JZ from the Lexus IS300

The factory 2JZ GE is out.

In the last part, we removed the wiring harness from the engine. Looking back, there are multiple ways to approach this. Instead of disconnecting every single plug from the engine, it could have been easier to disconnect the ECU, fold it aside, and pull the engine with the harness still attached. Either method works. Since this engine is coming apart and the harness will not be reused, separating everything made sense for this build.

With the harness fully separated, the next steps included:

• Removing the ECU box and unplugging remaining connections
• Disconnecting coolant hoses and AC lines
• Unplugging and removing power steering lines
• Disconnecting fuel supply from the block using a 17 mm fitting
• Removing multiple chassis grounds, including 14 mm ground points
• Draining remaining coolant and fluids

There were a few moments of coolant spilling everywhere and fighting stuck clips, but eventually everything was disconnected. At that point, the engine was officially free from the chassis.

We covered the full harness removal process in Part 1 of the 3UZ swap build.

Engine Hoist Setup and 2JZ Extraction

This was also a learning experience. A new engine hoist was set up along with an engine leveler to control the angle during removal. The leveler was bolted to factory lift points on the engine, allowing adjustment while lifting.

For someone who has only pulled a motor once before, this was a hands on learning moment. Hook placement, chain length, and balance all matter. Once tension was applied and mounts were cleared, the 2JZ slowly came out of the engine bay.

Just like that, the IS300 no longer had its inline six.

Pulling the 2JZ marks a huge milestone in the 3UZ swap process. The chassis is now officially ready for V8 fitment.

Picking Up the Toyota 3UZ FE V8

The next day, we picked up the 3UZ FE V8.

The engine came from a front end collision vehicle. It had been sitting for a while, which explains the surface rust on external components, but internally it shows signs of being well maintained. A Carfax report confirmed consistent maintenance history before the accident.

For a swap like this, maintenance is critical before installation. Since the engine is already out, it makes sense to replace everything that is easier to service now rather than later.

Planned maintenance includes:

• Timing belt replacement
• Water pump replacement
• Valve cover gaskets
• Front main seals
• Rear main seal
• Starter
• Accessory pulleys

This is standard preventative maintenance for a used 3UZ FE and ensures reliability once the engine is installed.

After maintenance, the engine will be cleaned and refreshed cosmetically before mock up.

Major Challenges for the 3UZ Swap

This is not a plug and play swap. There are several systems that need to be addressed before the 3UZ can run properly in the IS300 chassis.

1 Wiring Integration

Wiring is the biggest decision point.

Options include modifying the harness in house or sending it out to a specialist such as Phoenix for a full standalone or modified harness solution. If the wiring is not done correctly, drivability and reliability will suffer. This is one of the most important parts of the build.

2 Fuel System Differences

The 3UZ fuel feed configuration differs from the factory IS300 setup. The feed location and fittings are different, which means custom adaptation will be required. This is manageable but needs to be addressed properly for safe fuel delivery.

3 Power Steering Configuration

On the 3UZ, the power steering pump is mounted on the opposite side compared to the 2JZ. This creates routing challenges. One possible solution is converting to an electric power steering pump to free up space and simplify routing.

4 Exhaust Fabrication

The exhaust will likely be custom fabricated. This may actually be one of the simpler parts of the swap since custom headers or manifolds can be built to suit the chassis and steering clearance.

5 Drive by Wire Conversion

The 3UZ FE uses drive by wire throttle control, while the IS300 uses a throttle cable system. This means the pedal assembly must be changed.

Options include using a pedal from an IS250, IS350, or GS430 that matches the electronic throttle system. Proper integration of the pedal and ECU will be critical for smooth throttle response.

Subframe Modifications and Suspension Plans

While the engine is out, this is the perfect time to address chassis upgrades.

The front subframe will be removed and notched to clear the 3UZ properly. It will also be modified to run an offset rack spacer from Para Max. This helps prevent binding at full lock and increases steering angle while maintaining consistent steering feel.

Additional suspension upgrades planned during the swap include:

• Thicker sway bar
• Heavier rate coilovers
• Replacement of worn lower control arm bushings
• Replacement of worn caster arm
• Rear upper control arms

Handling is just as important as power, and this build aims to improve both.

Possible Additional Modifications

There are also optional upgrades being considered while the car is apart:

• Battery relocation
• ABS delete
• Manual brake booster conversion
• Power steering delete

Some of these may happen depending on budget and time. For now, the focus remains on what is required to complete the swap correctly.

Build Information

• Chassis Lexus IS300
• Engine Swap Toyota 3UZ FE V8
• Replacing Toyota 2JZ GE

What Comes Next

The 2JZ is out. The 3UZ is home. Maintenance begins next, followed by test fitting and mount positioning.

This is where the swap moves from teardown into true fabrication and integration. There is still a long road ahead, but progress is real.

If you are into Lexus IS300 builds, Toyota V8 swaps, 3UZ conversions, or custom engine projects, follow along as we move toward mounting, wiring, and firing up this V8 powered IS300.

The inline six chapter is closed. The V8 era is officially beginning.