The wiring and the module programming. Are they both H-shaped. I know for My2005+ with the updated CEM it was possible to reconfigure the CEM as it was modular. For the pre-facelift H-shaped modules, I am not sure. Maybe T5Luke knows. Basically it is wiring and then modules. You will need to be due ...

Are you planning to keep the manual trans or swap over to the auto? Staying with the manual may be easier but there will be some work to do between the back of the engine and the trans if you do. AS mentioned above I believe there are some wiring changes from the 2003 and 2004 C70's over previous ve...