Transmission Compatibility
Planning matrix for common engine/trans pairings. Adapter and kit choice drives details.
| Engine | Common transmission | Pros | Cons | Notes |
|---|
How to compare transmissions for a swap
Practical context
Transmission strength is only one criterion. Compare gear ratios, shifter location, physical size, bellhousing/adapter solution, clutch/flywheel availability, starter arrangement, speed-signal strategy, mount/crossmember, driveshaft connection and service-parts availability.
A gearbox that fits one engine through an adapter can place the shifter in an inconvenient location or create tunnel/exhaust conflict in an S13/S14. Confirm the exact adapter manufacturer’s stack-up and recommended clutch parts rather than mixing forum part numbers from different systems.
The matrix is a planning shortlist. It does not certify torque capacity, fitment or kit compatibility. Use current manufacturer documentation and measure the final engine/transmission position before ordering a driveshaft.