Mine does it as well (not so much a clankin but you can hear moving parts). Especially when its cold. No problems though. I would expect to hear something after all the clutch is physically moving in and out.
2013 5.0, 6 speed manual, Brembo Pckg, 3.73 gears, American Thunder 40 series Flowmasters, 1 inch Lowering springs from Roush, J&M LCA, J&M Adj.Panhard bar, 20% Tint all around.