When I swapped a diesel into my old disco. I unplugged the trans and Engine ECU. The speedo would work and the abs would work, but when I gave it a tach signal, the ABS would error out because it didn't see the Engine ECU. What I'm saying is yes, its doable. You need to flash the immobilisation out of the engine ECU. And just hook all your stuff up. It may be easier doing a virtual dash using realtime data from the engine ECU and just leave the instrument cluster board plugged in somewhere.