clicking until clutch slightly depressed

[Zogbert]

'72 C10
250ci
3OTT

Just had the driveline serviced by a highly regarded transmission shop
- flywheel machined
- new pressure plate
- new clutch
- new u-joints
- new hanger bearing
- rebuilt rear end

Now has a clicking noise that corresponds with driveshaft RPM. In first gear faster than second; second faster than third, which leads me away from the speedo cable.

When I depress the clutch pedal as little as a half inch, the clicking stops completely. It will click at idle in neutral sometimes, but not always.

There's no vibration associated with the clicking. At this point, it's more of an annoyance.

Thanks in advance.