For Sale is a good used McCulloch Chainsaw Clutch.  Make sure you saw takes the straight bore, with no threads as shown.

Fits:

McCulloch Super Pro 40

McCulloch Pro Mac 510

McCulloch Pro Mac 300, 310, 320, 330, 365

McCulloch Mini Mac 110, 120

McCulloch 3200, 3214, 3216, 3516, 2316, 2318, 3205, 3505, 3805,

MACCAT Super 16, MACCAT Super 18