Call this company. I had this link in my file.
http://www.moderndriveline.com/Techn...its/tremec.htm
I have bought several trannies from D&D Performance, great people to do business with. Check with them.
One of these companies should be able to give you a part number so you can buy the seal locally. You can take the old seal to a real parts store or a industrial bearing/ seal supply house. They should be able to match it.
http://www.ddperformance.com/
Dwight