Amsoil ATF would be a great choice. With amsoil atf you have the added benefit of a more robust fluid that can remain in service much longer than any Dino ATF. If you decide on Amsoil, get in touch with one of the site sponsors here. Good guys for sure!
If you dont want to order the fluid, you can always go with Mobil 1, Pennzoil, castrol...... The most important thing is do you want to pay extra for the added benefits of the synthetic ATF. If dino ATF is changed regualarly it will work just fine. Make sure you preform a flush to get the full benefit of whichever fluid you choose.
And one last thing, be sure not to forget to add some measure of filtration to the mix. In your application a Magnefine would work beautifully. Very inexpensive and it will ensure that any debris dislodged by the flush will be retained instead of distributed throughout the transmission.
Castrol Import and Pennzoil Multivehicle are great not overly expensive ATFs.
Don't forget Mobil1, RoyalPurple, Amalie... for other full synth options.
Being a '96, just about any DexronIII clone will work. I myself prefer full synthetics. If on a budget, I'd consider a synth blend like MerconV.
The shift quality of what the Castrol Import provides is superb for a Dex III product, I actually like it much better then the Maxlife Dex/Merc that we're running in our Tacoma.
i have a DEX3 tranny in my tacoma.. i have used Maxlife ATF and liked it. i wanted to go synthetic so i went to amsoil universal atf.. i love the amsoil.. cant say enough about it.. you can go wrong if you wanted to go the dino route with maxlife or castrol as noted above. just drain and fill it more often (every 10k miles) you can drain roughly 4-4.5 qts per drain and fill.. not very pricey imo
The original ATF spec called for Dexron-III, didn't it? Or even if it called for old Dexron-II or IIE (I don't know when Dexron-III replaced Dex-II), use any brand of ATF that says anything about Dexron-III on the label. I feel that the name brands are better, and that synthetic will live longer.
Dexron-III in no longer "officially" produced, but is still widely made under other names. If the labels says anything like, "recommended where Dexron-III was originally used," that's what you want. Do not use anything that does not refer to Dexron-III on the label.
Its probably Dex III like what unDummy said. Back in 96 there weren't as many ATF specs as there is now. But you can consult your owners manual or call a dealership.
GM is no longer licensing Dex III so will have to go with one of the universal ATFs that meets Dex III specifications.