KNOWLEDGE BASE: want to share your knowledge of this engine swap? Email me your tips and I'll post them here.

GEARBOX: There are a few options - basically any gearbox that fitted upto an m10 has the same bolt pattern and should fit up to the s14. Most common is the OD getrag that came in the e21 3 series and is a common upgrade to 2002's. This box bolts right up and fits the transmission tunnel without amy major work.

This option will require you to have the motronic sensors for the ecu installed into the bellhousing. You'll also need to shorten your prop.

Another option is to use the getrag 265 close ratio box that came as standard with the European m3. In it's favour it has the sensors already installed, it's a close ratio and it has the dog-leg gear pattern. This box will even install with an uncut m3 prop. Downside is it's a bigger box and you'll need to cut off the top of transmission tunnel to make it a little wider and taller.

DIFF: As you like, but most people with an OD box will run a 3.9:1 or higher where as a close ratio box is better suited to a 3.64:1 or lower. But this really depends on the use of the car. LSD options from the e21 3 series.