My guess is the longer one is the holder bolt, the shorter one is the bearing cap bolt.
For sure i can say the bearing cap bolt is 60mm (motogrid.com fish) long measured from under the flange to its end. The other one is the holder bolt. Its more special (I think its harder) so its length is not on the fish.
That's not a "b", its a "9". The circle with the line is an 8.
ISO bolts get harder as you go up. Maybe they all do?
OCICBW