It appears the most popular gear
oil for a Tremec trans is GM Synchromesh or the aftermarket equivalent made by Pennzoil.
As I seemingly can't buy either of those in Brisbane, what are you using for your Tremec?
Repco and Supercheap are almost identical in that they have the base Castrol and Caltex gear
oil and some home brand variant and that's it.
Mine is a TKO600 if it makes a difference.
Thanks!
Craig