Puzzling clutch noise

[Conaway2]

We just installed a new Schwalm’s long block, rebuilt transmission, bell housing and V8 clutch with new pressure plate, throw out bearing, pilot bearing and disk.

The engine runs beautifully, but there is a metallic tapping noise coming from the bell housing…that disappears when the clutch pedal is pressed in. I haven’t heard the noise myself - just what the guys in the shop today have told me.

What could cause this ? Possibilities I‘ve thought of are flywheel safety wire sticking out too much, maybe clutch disk in backwards ? - not sure it can even be installed backwards…..

Thanks for any ideas -
Jim