I would think that the longer plungers would limit the amount of travel into the coil thus not generating a full strike from the pop bumper ring. It would probably still work but more than likely wouldn't have the punch a shortter plunger may give.
Is there an earlier parts catalogue than 1982? That is a good 3 to 4 years after Sys 1 machines were built and there is every chance things may have changed in that time when they went to Sys 80 machines???
