You're probly right,i just know a friend of mine learned the hard way the 655 was normal threads bc he stripped the nut on the threads by goin the wrong way first
Better the nut than the crank. I have a pdf manual for those saws if he wants it. The 10 series MACS have a tapered shaft on the clutch side like the FW side on most saws. They do use a LH nut.