Knocking after installing new flywheel

[newshirt]

I just installed a new stock flywheel, pressure plate, and clutch. Now I get a clicking sound when depressing the clutch petal. The clicking intensifies to a full knock when I press harder. Once it starts knocking, it continues even if I release the clutch petal. The click sounds like it is once per revolution.

The clicking does not occur when hand-cranking or cranking with the starter (with or without spark plugs). It only occurs when the engine is running, and the clutch petal is depressed.

What I have tried:
1. Used short starter bolts
2. Whacked the ring gear with a big hammer to make sure it was seated
3. Hand-turned the new throw-out bearing to make sure it was free

Any ideas what the click and knock might be?