Technically to be legal you'll need to swap from the Getrag box to the ZF box. Both have the same ratio's, both bolt to either motor, but you'll need to get the proper drive shaft too. When I put the M50 2.5 in my Z3 I stayed with the ZF box, but I'm going to STU so I can run vorshelag motor and transmission mounts, along with my aluminum flywheel, and the wonderful M50 intake manifold.