The number etched on the pinion will be the variation from standard height.
Refer to the gear you are removing to get the variation in setup height.
From the early 80s Mitsu reduced dependency on the pinion markings though and just uses gauge blocks to select the pinion shim.
This procedure leads one to use the shims that came with the original housing to set height. This has been working well with the setups I have been doing.

With that tight 4.22, I would drop the ring gear out and investigate if it is the pinion preload that is tight. Might be that the seal is dry? It might be the diff preload that is tight.

You will love the short gears in a Starion, I run 4.22 at some roadcourse events and 4.62 at AutoX and hillclimbs.

While you are in there check the stack in the diff clutches. Many of them come ABBA, if you swap the inner and outers to ABAB you get a stronger lockup.