Well Blackrain, My nemesis Manual shows Part#G73921 to be a Bearing 12 x 21 x 5, and my GST manual I got from the 'Bay shows the Part#G73914 to be a Bearing 8 x 16 x 5 The first image is the GST manual page 5 and the second is the Nemesis manual page 5. As you can see all of the parts except the bevel gears(the most expensive to manufacture) are different. Just see for yourself...