When I first went to remove the swing-arm, the pivot bolt was extremely tight until the nut was backed off by two or three turns. The width of the swing-arm pivot was less than the frame mount, and excessive torque had been used to actually flex the mount, apparently from the factory. With the bolt loose, the mount returned closer to it's original location, leaving a gap. I fitted a 1/16" thick washer, which snugged things up.
The stock FT bearing is a single row needle bearing with a 20mm ID, 26mm OD, and 20mm length. The '82 Honda CR480 uses a double row needle bearing that is 20x26x30. The better CR bearing will fit right into the FT swing-arm, in fact, it looks like they designed it that way.