Here's why:
* Bell Housing Differences: The bell housing on the R33 gearbox is designed for the R33 engine, and it won't bolt up to the R34 engine. The bolt patterns and overall dimensions are incompatible.
* Transmission Input Shaft: The input shaft of the R33 gearbox is a different length than the R34 engine's flywheel. This mismatch will prevent proper engagement and could cause damage.
* Gear Ratios: While the R33 and R34 gearboxes share some similarities, they have different gear ratios, which can affect performance and drivability.
Possible Solutions:
* R34 Gearbox: The only guaranteed way to get a gearbox that fits is to use an R34 gearbox.
* Adapting the R33 Gearbox: With significant modifications and custom parts, you might be able to adapt an R33 gearbox to fit the R34 engine. However, this is a complex and expensive process, and it's not recommended for most enthusiasts.
Important Note: Before making any changes to your drivetrain, consult with a qualified mechanic or professional to ensure proper installation and safety.
