I am in the process of putting a Digital Dakota Speedo/Tacho combo gauge HLY-3016 on my Speedmaster right now. DD gives you the option of running with your stock speedo cable or a sensor. the senor is what I'm going with so that I can eliminate the cable off the forks.
The DD gauge is 3 3/8 round. So I needed to change the face of my console. This of course required some fabrication on my part, which is not that hard.
