I might be just full of bull, but I seem to remember reading somewhere that you don't use teflon tape on fuel line fittings, and the reason escapes me. Do you think this is only rubbish?
The first thing one should do is establish what type of fitting you are referring to. Inverted flare as well as AN flared type fittings require no sealant.
The only fitting that does is pipe type thread which is a tapered thread. There are several different acceptable sealants that can be used. The primary concern with the tape is it sometimes leaves strands behind that can find there way to the fuel system/ carburetor
