The Bully spring height gauge has an adaptor attached to the anvil that has a recess with the proper depth to clear the current Bully spring nut.
It will work on the older Bully spring nuts with no issue.
It will also work on every other clutch on the market that utilizes a 10-32 Flat Head Cap Screw with an aluminum retainer as the ID of the gauge will clear the screw and register on the retainer.
Kermit Buller is a pretty smart fellow who made a universal tool that anyone serious about clutch maintenance should own.
I have four of them. One at work, one at home, one at my trackside ProShop, and one in my tool kit that travels with me to every event.
I replace my work unit once a year, as I build quite a few clutches, and prefer to have a fresh gauge on my build bench to ensure linear accuaracy.