Most likely the spacers will go between the sensor and where it mates with the block.
If your new sensor is to close or to far from the flywheel it wont work.
So it would be block, spacer, sensor.

 

so the spacers would go on the two screws first then the sensor with the metal piece after it or the metal piece off the sensor first then the spacers then the sensor then the nuts. i tried it both ways the sensors not loose it dosent wiggle at all. i just wanna make sure i have it right.