I made the conversion to the A-10 unit last year. I installed Tach, Speedometer, water pressure, fuel, trim and voltage. You might want to consider an engine temp gauge. I have a clock and water temp in my LMS-160 graph, so I dont miss those features. You will loose livewell temp, barometer and compass features along with the alarm system which were part of the BP-101 I had……not sure if they are all in the BP-100. BC does sell an add-on alarm if that is important to you. The conversion took half a day, but I didnt rush it. The kit supplied by BC works on Mercury, but you might need a different trim gauge with the Johnson. The A-10 touch pad controls, bilge pumps, livewell airation & recircultion, switches from left to right gas tanks …so you can read either and works great. There are directions for installation of the kit in the parts section of the BCB web site….they are pretty straight forward. Ask if you need further info.Bill