Randy

Those are used when the pressure plate is built (or rebuilt) to set the height of the arms. there is nothing to be adjusted after it is set up.

My personal rule of thumb, after a few cases like yours over the years: If I remove an engine, replace a transmission or split a tractor for any reason - replace the clutch!
Clutch/pressure plate sets are best way to go.
It is so much work to take everything apart to do a clutch that doing it when it is right there just makes sense.