all kinds of kit to do it and details on how to use arduino etc with hardware from digi-key.. all too complicated or expensive for me.... :) easiest is tone ring and pickup with wire into box under dash with a short cable drive into back of speedo But mine works mechanically so i never got any further. was gonna do one for an electronic speedo t5 , pluses in via conversion to pulses out into the motor drive turns speedo at correct rate.