Here's a lift from the TTC site:
http://www.ttcautomotive.com/English/faq/faq.asp#13
Technical Questions
What type of lube is recommended for my TREMEC transmission?
The following types of lube are recommended:
TR-3550/TKO - GM Synchromesh or Dexron III
TR-3650/T-45/T-5 - Dexron III
T-56 (Ford and GM) - Dexron III
T-56 (Viper only) - Castrol Syntorque