I have an adapter somewhere. I'd have to look around to find it. You need to consider what Mark suggested. Recalibrating the speed-o is the right way to do it. The adapter will get the needle to read the right MPH but it will cause your odometer to register mileage incorrectly. It will also cause problems with torque converter lock up. If you have a lock up torque converter what ever speed your computer calls for lock up will not happen until a much higher speed. If your converter should lock at 40 it won't lock until 68 mph. That speed is determined by the chip. The problem is that the adapter reduces the vss so the computer sees an incorrect speed. The adapter is a band aid fix. Recalibrate it and you have no other issues. If I come across that adapter I'll put it on the side but I hope you decide to do this right instead.