Mechanical components of a 14o or 140 speedometer will still be required.
To have the speedo read correctly, one could put the guts of a 140 mph speedo behind the new 14o mph face, but another option is to simply recalibrate the existing speedo head for a 14o mph face.
Speedometers are calibrated using magnetism. When you install a new drive, it has no magnetism in it. AutoInstuments 'zaps' it with a magnetizer, and the speedometer is then connected to the calibration machine. Autoinstruments then takes a demagnetizer and literally sucks the magnetism out of the drive a little at a time, until a correct calibration is achieved. If you go too far, you have to zap it again and start over
so just having a speedo shop recalibrate one's current speedo might be a good option for people doing a conversion. Especially if there was a "group buy" to have a bunch of speedos recalibrated to 14o mph all at the same time.
Last Edit: Mar 31, 2014 14:42:51 GMT -5 by Steam McQueen