Nero, I've been in the same position numerous times. Last year I told my friend Brian that I felt like a guy, and despite the fact that he's accepting of gay men and lesbians, he decided I was just crazy and delusional. He said that somehow, I must have gotten it into my head (as a child) that I was male, even though I wasn't, and that it was probably to compensate for some other shortcoming, and then persisted into adulthood, so now I was just suffering from that childhood delusion. All I needed to do, he said, was start trying to accept myself as a woman, start dressing like one, and acting like one, etc, and maybe even dating guys, and I'd be okay. Any time I tried to bring up the issue after that, he just blew it off or started a fight. I didn't exactly lose him as a friend, though that might have been better than the reaction he gave me. I guess you just don't know until you talk to people... and I'm of the mind that if someone doesn't accept me as I truly am, they don't deserve my friendship. I realize that's callous, and difficult to do with longtime friends like yours, but you never know. I'd say just test the waters first... try to figure out what his views on TSs are before you actually admit to it. You might be pleasantly surprised, or you might get a reaction like Brian gave me... going all Freudian, when I'm the one who's a psychologist. Anyway, good luck in whatever you do.
Rafe