The vent kit vents both distributors. The purpose of the vent kit is to keep the ozone away from the rubber belt. The rubber belt is connected to the primary drive of the primary to drive the secondary. This means there is an opening between the two distributors. If you look at the assembly you will see it is really just one base assembly. The air is blown into the vent line, through both distributors and then out again hopefully with the ozone in tow.
Ciao,
Adrian
911C4

 

Thank you, Adrian and others. I knew there must be some reason for only one vent. My mind is still trying to fast forward 25 years from my '69S to my newly purchased '94 RS America. Everything is the same ... and yet different.