Go to AutoZone or oriellys Auto parts and ask. Using the Lucas transmission fluid or Valvoline is your top choices as well as mobile1 but if using a manual transmission Royal purple is more for high end performance shifting.
Is what I was told and read. I already love using Royal purple motor oil so I used the tranny fluid as well, just did a transmission swap like 6k miles ago and since it was a used unknown transmission (how it was treated) I like Royal purple. If you have time to order some online, order something with synchro mesh in it.