Tremec in my 99 GT?

I'm sure someone will be able to enlighten me on this one.....I've always thought my 99 GT had a T5 in it, but the other day I was underneath it and noticed the unmistakable "tremec" word on the side of the gearbox. I've always read that the TR3650 was introduced in 2001 GT's...am I missing something here?? I thought for sure that a T5 would say "Borg-Warner" - not tremec. Do I maybe have a different style tremec?