I think it’s a good idea to seal the exhaust socket the best you can. You can use the RTV silicone or you may want to consider purchasing the new EVO exhaust socket and use the gasket sealing ring. Regardless of which method, I would highly recommend using 4 springs in lieu of 2. My son’s exhaust seals well with either method as long as we have 4 springs.  If you use the RTV, you’ll find that it doesn’t last long due to the heat and vibration, so you may have to reseal every couple of runs. I really like the new gasket seals and socket. It is difficult to install the gasket without breaking it though. I found that heating it up helps with getting it around the socket.