That is very interesting, and is something I will want to have a closer look at. With the Rover Overdrive system, it was always felt that components in the overdrive unit could "burn out" and as a consequence, was never recommended. It is no secret of course that the Triumph Dolomite Sprint"s Overdrive allowed for the unit to engage in the upper three gears. Don't know if it ever caused any problems. Just thinking about the modification - is there a great deal really in adopting that feature ? I would say "NO', but if it works with safety and can be used with a certain amount of understanding the system, it might be okay. Rgards Styria