Ok, here's what I done:
I have a small number of options on my drill press as far as spindle RPM. So I'm going to use the 1720-3100 RPM settings along with a "tool" I put together to test out the clutch.
The bolt and nut, along with some washers, fits really well. The lack of threads on the end of the bolt lets me fit it in the drill press.
For reference, here is a stock clutch at rest, with the shoes fully retracted.
At 1740 RPM, the clutch is still closed. At 2340 RPM, the clutch is open. So that gives me a rough idea of what the aftermarket clutch should be doing.
The aftermarket clutch at rest, and at 1740 RPM, stays closed.
At 2340 RPM, the clutch starts to open, but not fully.
At 3100 RPM, the clutch is fully open.
So the aftermarket clutch seems pretty close at this point to the stock one. I've got it installed in the engine, and this weekend I hope to try it out.