Recently, an air leak introduced itself in my Triumph TR7. After some playing with soap and propane, I found out the leak was from the rubber carburetor (SU HS6) mounting plate. As with many things on this particular English car, it was incomprehensible that they couldn't think of a better design (i.e., one less prone to failure). This is the failing part, it consists of a metal plate with a rubber gasket vulcanized to it.
The bolt ends are also vulcanised to the rubber, but they're not fixed to the metal plate. You can wiggle them. Consequently, the carbs are mounted to the manifold only with those vulcanised connections to the rubber. They're doomed to come loose because of the vibrations of the engine, which is exactly what is happening.
I could buy a new set but i don't think they'll last that long, especially the lower quality aftermarket ones. So, I was thinking of prying the rubber loose, and welding those bolt ends to the mounting plate. Then, the rubber gasket would be replaced with a nylon one. But I'm worrying about defeating the purpose of the original rubber gaskets. They're meant to protect the carbs from vibrations. Welding those bolt ends to the mounting plate and using harder nylon gaskets may let through more vibrations to the carbs. On the other side, the MGA for instance, with the older H4 SU's do use bolts directly mounted to the manifold, and harder rubbers.
I hope some of you have experience with this kind of problem. Do you think I can remake this carb mounting as explained, or will that damage the carbs over time?