Here's why:
* Bolt patterns: The 1JZ engine has a different bolt pattern for the transmission than the 4Runner. This means the transmission won't physically bolt onto the engine.
* Input shaft: The input shaft of the 4Runner transmission is designed for a different type of engine, and it won't be compatible with the 1JZ.
* Gear ratios: The gear ratios in the 4Runner transmission are likely not suitable for the performance characteristics of the 1JZ engine.
To make a 1JZ engine work with a Toyota 4Runner, you would need to:
1. Find a transmission compatible with the 1JZ engine: This might involve using a transmission from a different Toyota model, such as a Supra, or a custom-built adapter.
2. Modify the engine or transmission to match: This may require machining, welding, or other custom work to adapt the bolt patterns and input shafts.
3. Consider the gear ratios: You might need to adjust the gear ratios in the transmission to match the performance characteristics of the 1JZ engine.
It's important to note that this type of conversion is a complex and challenging project that requires specialized knowledge and skills. If you're not experienced with engine swaps, it's best to seek professional help.
