What’s this hole for 1973 RS

[mobius911]

My RS has the black box (no charcoal). IIRC, the exit vent line from it (the smaller tubing) goes to a Y-connector that has a drain tube from the brake reservoir overflow port. The combined outlet of that Y connection is a drain tube that goes through a clip in the cardboard fuse cover, and then through a grommet in an opening in the front panel. That little square opening in the cardboard cover is where the clip mounts.

[NorthernThrux]

I have the hose clip that mounts on the cardboard if anyone needs it. Just pay the postage. I bought it in error before I learned it was only for ROW cars.
The black tank under the cowl has a tendency to crack over time and thus vent fumes. So finding a good used one is likely impossible. There are new ones made. You also need a square section giant o-ring to mount it under the cowl. NLA, but you can get the essentially correct one from McMaster-Carr. I have a few posts on this somewhere, including dimension, maybe in my build thread. The modern replacements (part number 901.201.618.22) are all round, which is wrong.

Ravi

EDIT: Here is the info. https://www.early911sregistry.org/fo...re+o-ring+tank

[fourteenten]

I think I have a 2.73 dated 85L tank currently in my RS. I am considering to put the original repaired 5.73 dated tank back in. Let's talk.

Cees

[RSTarga]

I thought that the plastic tanks aged out. Most plastics don't last 50 years, even less when in contact with gasoline.