Dumb Question re: master cylinder

[Darwin]

I'm converting from single suicide master to power discs up front. Is it neccessary to put a gasket between the booster bracket and the firewall or does that thin metal plate with the rubber boot in it act as the gasket?

 

[RedFish]

I'm converting from single suicide master to power discs up front. Is it neccessary to put a gasket between the booster bracket and the firewall or does that thin metal plate with the rubber boot in it act as the gasket?

There is a foam like firewall gasket that goes there but it's not absolutely necessary. most any sealant would work.