Lexus IS300 8HP Swap Guide
Everything you need to know about fitting a Dodge ZF 8HP transmission behind a 2JZ-powered Lexus IS300.
Why Swap An 8HP Into An IS300?
Stuck with a tired IS300 automatic, a weak W55, or a clunky R154? The ZF 8HP gives the IS300 faster shifts, stronger drivability, and a transmission platform that can grow with serious power goals.
Our IS300 kit is designed around the modern Dodge 8HP transmission behind the 2JZ platform, with the supporting parts needed to make the swap fit cleanly.
What Is Needed?
A typical Lexus IS300 8HP swap needs the core transmission hardware plus chassis-specific fitment parts.
- Dodge 8HP70 or 8HP45 transmission
- 2JZ to Dodge 8HP adapter plate kit
- IS300-specific engine brackets / forward motor mounts
- Transmission controller such as MaxxECU or Turbolamik
- IS300 8HP transmission mount and crossmember
- Driveshaft
- Transmission oil cooler and fluid delivery parts
- Shifter or shift selector solution
Optional parts include a clutch position sensor and clutch simulator if you want virtual clutch behavior.
8HP45 Or 8HP70?
While developing our 2JZ adapter plate for the Dodge 8HP70, we also tested the Dodge 8HP45 from a V6 RWD Charger as a budget-friendly alternative.
The 8HP45 and 8HP70 are very similar in overall size. The bellhousing bolt pattern, transmission mount, and output flange can vary depending on the unit, but the external dimensions are close enough that the 8HP45 does not create a major tunnel-clearance advantage.
Note: The 8HP45 can be a useful option for moderate-power builds, but we do not recommend it for applications over 500 WHP.
IS300 Tunnel And Engine Fitment
The Lexus IS300 transmission tunnel is tight near the firewall. Compared with larger manual swaps like CD009 conversions, the Dodge 8HP casing fits the tunnel more cleanly and usually requires only minor clearancing.
The tightest area is around the bellhousing near the firewall. To simplify installation and increase clearance, we move the engine forward by 5/8 inch using our custom stainless motor mounts. With this setup, the transmission fitment becomes cleaner and more straightforward.
Important: The transmission must be shaved before installation, as shown in the general 8HP swap guide.
Mounts And Driveshaft
We designed IS300-specific engine brackets to move the engine forward and help the 8HP clear the tunnel. The transmission mount is also chassis-specific.
For the driveshaft, we typically use a 3.5 inch aluminum driveshaft with 1310 joints for a direct bolt-on fit with the OEM differential. Higher-power setups can use a 1350 driveshaft, but that requires a 4-bolt differential adapter.
Controller Options
The IS300 8HP swap can be controlled with systems such as MaxxECU or Turbolamik. MaxxECU is especially interesting when you want one ECU strategy for engine and transmission control.
On our development car, we used a MaxxECU Sport ECU relocated under the driver seat, 1ZZ coils, 1000cc injectors, a GM electronic throttle body, a BorgWarner S366 turbo, custom intercooler piping, and supporting fuel and wiring upgrades.
For a six-cylinder engine, MaxxECU Race is usually the stronger choice because of the additional inputs and knock capability, but the right controller depends on the complete build plan.
Start Your IS300 8HP Swap
Send us your IS300 build details and we will help you choose the right adapter, mounts, driveshaft, controller, and supporting parts.