NEVER.. EVER cut a gasket.. you just intentionally created a fail point that WILL LEAK. No silicone is impervious to gasoline either. Silicone has a molecular structure that is very stable overall at a wide range of temperatures and pressures, and its generally inert structure makes it safe for a range of applications from baby food to engine coolant. However, fuel and oil are some of the only substances that tend to break down this molecular structure, making it unreliable for use in your vehicle’s fuel lines. These substances tend to act as a solvent on your silicone, essentially dissolving it gradually.
