if you look on car-part.com, you can get an idea of what was offered in certain years.
i did a search on 93 r&p and got this.

Rear Axle, (3.0L, 6 cyl), 4.63 ratio
Front Axle, (3.0L, 6 cyl), MT
Front Axle, (3.0L, 6 cyl), AT, 4.63 ratio
Front Axle, (3.0L, 6 cyl), AT, 4.88 ratio (SR)
Rear Axle, (3.0L, 6 cyl), 4.88 ratio (SR)

so it looks like you have 2 gear ratios that are out there. if you look at axle-rear diff, it shows some locking diffs available, but i did not look it up for your area.

'88 Raider. 2.6L dead...2.4L swap in progress, AT, 33's, 2 bouncy seat,AC, CC, 2.25 exh, 2" Tbar, 2" BL, rear DB, rear LSD,4.90's, SW hubs,gen2 uca's, KYB shocks, snorkel, elec fan, MSD.

'99 chev k3500 crewcab
'15 Subaru XV
'03 BMW i325