The Supra diff which we have been using over here where we never got a LSD in our cars is the 87-93 MkIII Supra which is properly called "MA70".
It looks like this:



In North America the ratios aew:
3L Turbos (87-88) - 3.90:1.................manual box
3L Turbos (88-92) - 3.73:1 ...............manual box
3l Turbo (87-93)...4.3:1..................autotragic slush box
3.0 n.a. (87-92)....4.3:1................all, and LSD with the "touring package"

The mounting kit is USD300, and to bolt up the propshaft there is a companion flange for around USD85 and a weld-in yoke ---the other half of the u-joint for around USD18-19
The u-joint is a Spicer 1310 available everywhere, here it is maybe USD20.

In North America we got only 3.64 open diffs for 5 speed XR4Ti and Scorp V6 (all), and 3.36 for XR4Ti (commonly referred to here as 'Xratty' cause the 4 looks like an 'A') with the horrible C3 autotragique.

I started doing these kits cause we want the 4.3 ratio for gravel rally but it turns out that when people bin the Type 9 Ford box and use Borg Warner T5, that all the USA T5s come with such tall 5th that the 4.3 is pretty good even on road cars when the 5th is 0.72 or 0.63.
So now we have a car that rips hard 1st thru 4th and use the 5th for highway cruise.
Top gear OVERALL with a 0.82 top and 3.64 is 2.98:1
with a 4.3 and a .73 is................................3.14:1
with a 3.9 and a .73 top is...........................2.84:1

Even the 4.3 with the nuts overdrive of .73 is only 5% shorter than original.
4.3 with the 0.63 is overall 2.7:1 9% taller than original.