Not to start the debate of how much clearance is needed or the definition of "running fit" but this is why you need clearance on the bushings of the triple gears
The bearing seized to the pin on a rebuild some 30 years ago more than likely from the start. This is out of a very low mileage speedster, maybe 2500 to 3000 miles.
As the triple gear wore the bushing OD, it cocked and cut into the flywheel about .025", as seen on the left. The ware on the right side was due to the thrust surface was well worn and the bearing had seized at some point but freed up with a lot of slop for clearance.
The triple gear also got into the flange of the reverse drum and machine a very sharp knife edge. Drum on left has a flange, on right you could almost shave with the edge.
Mike, If the bushing is reamed by hand you can have it crooked to the gear. It will run like a bent wheel and then seize on the pin. If the bushing is reamed square the the gear you dont need to hog it out to live. Iam glad you posted a picture so others can better understand whats going on. Scott
Great Info!!!!!!!!!!!!! Bud.