Whats this bigger rubber on ebay ??

guy on ebay selling a 32/34 dmtl weber carb quote :
"HAS A LARGER RUBBER AND BASE PLATE COMPARED TO THE PIERBURG RUBBER ALLOWING MORE FUEL AND AIR INTO THE ENGINE"

Item number: 140076828020

any what its off ideas? the guy wants to keep it a secret?

Similar rubber as found on the WN code Audi Gt with the car engines.

The rubber wont give any extra power unless the original was blocking the airstream.
I did a similar mod on mine but i used a solid plastic block on mine.
If you took the gasket for the carb base to a laser cutting company theyd be able to create these insulators for you, although theyd be solid stock.
I didnt have a problem with mine though.

Cant see why he want to keep it a secret though…..
The carb may be almost brand new but a new one isnt going to be a huge amount extra and he seems to be asking a lot for a used carb….to me anyway.
Aldon Automotive do still supply carbs i believe, you could try them as a source for the beses too.