If you have an F-series diff, you can get another ratio from most Toyota's pre-1985 (Supra, Soarer, Celica, Crown, Cressida)
If you have a G-series diff, you'll be looking at post-1986 (Supra, Soarer, Celsior, Cressida, etc)
The GX71 came with either an F or G series, depending on the year...