I am trying to determine the difference between a few FD transmissions. Specifically, I am trying to see if any are a series 8. I have searched and found "the S8 box is missing the 1-2 sensor on the driver's side of boss near the shifter housing". I am having a hard time finding out what the 1-2 sensor looks like. Can someone elaborate? Perhaps with a picture? Is the part number (N3XX) stamped on it somewhere?

 

If you're worried the late box has an altered casting, so it won't take the sensor, it's just been blanked off with a short 17 or 19mm hex bolt on the late cars.

The sensor in question is the only 4 wire one on the gearbox, pic -

 

so the s8 still has the hole for the sensor, it just has a bolt in it? or there is no hole for the sensor? is that the only difference externally between the series?