My understanding is the extra clearance is in the bearing race not the fit on the shaft or in the case. So on one of my old [yamy] 360's on the mag side because the bearing is super tight on the shaft & equally tight in the case it's being externally squashed & internally expanded, so i use a C4 [or should be--been a while], but on the primary side only the outer is very tight & crank is a zero clearance sliding fit so i'd use a C3.
Talking Tin plates on Honda cranks i made a heavy band to clamp around so i could beat it a [little bit] but spread the load so as not to dent it--[was the plan anyway lol] so as to align the crank after replacing the rod assembly. Honda RS125 that was, about "92 by memory.
Back to bearings--on my bucket i used fiber caged high speed bearings on my TF100--well it made me feel i was going fast if nothing else. Had no problems with them ever.
