Your new spacers or spring shims will have no effect on how much the screw sticks through the hub. The old spring screws, which you've now turned into spacers, screw down tight to the studs on the hub. I wouldn't change the height of those old screws/spacers. That would alter the spring compression and how much screw sticks through the hub.
I think the only way you'll know if those new spring shims/spacers you plan to add are too thick would be to assemble the clutch with them and see if it still operates.
I think the only way you'll know if those new spring shims/spacers you plan to add are too thick would be to assemble the clutch with them and see if it still operates.
