I have a 1976 vintage aluminum case 833-od. The case is tapped for a reverse switch, but in it's place was a steel plug with a spring and ball bearing. The plug looks to be a factory deal, and not a cobble to fill the void from where the switch is supposed to be. I'm not too familiar with 4 speeds, but what would be the reasoning for the trans "not" to have a reverse switch? Am I right in "ass'uming that I can remove the plug, and replace it with a reverse switch for my application?