what type of tranny fluid in the tremec?

I emailed Tremec a week ago about which fluid to use, because I was interested in Red Line synthetics. Here's what they said:

"Our recommended fluid for the TR3550 family is GM synchromesh. Due to
the materials internally, we have not tested any other fluids. "

Jon A. Vieth
Product Line Manager
 
when i bought my tremec from holcomb i told them that i wanted the recommended fluid for the tko 500 and they sent me royal purple synchromax tranny fluid. so thats what im gonna stick with...and if it hurts it than holcomb is gonna be givin me a new one
 
ECU5.0 said:
royal purple synchromax tranny fluid.

i am at the point of having to change the fluid in mine.its been a little notchier then i like running gm synchromesh.has anyone had good luck with the redline stuff?i want smother shifting if possible,but i dont want to hurt the trans either.ive heard a couple of people say sychromax,mtl,or synthetic atf from royal purple.so are any of these any good?