Actually silicone and gasoline are a serious bad combo. Gasoline can cause Silicone sealants to balloon up to many many times their original size and then pieces fall off plugging fuel lines and carbs up.
I once as a kid made the mistake of siliconing the sending unit into the tank on a 52 Chevy 3100 custom cab pickup and about a mile and a half from my girl friends house had to get under the thing and with a wire dig silicone out of the petcock valve in the bottom of the tank. The results were I smelled like gasoline had chemical burns on my right arm and the big date we were going to be going on ended up with her mom a nurse. Washing my arm and applying some kind of ointment to it. Needless to say I haven't let Silicone sealers get anywhere near gasoline since.
I took another 4 attempts to get all that orange crap out of the tank.