Yes, all bearings MUST have pins! The #1,3&4 only have one pin because they are full circle bearings. #2 has two pins because its a half shell bearing so it has one on each case half.
(If you had my video this question would not come up
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The pins must be there to KEEP THE OILING PASSAGES IN THE BEARING ALIGNED WITH THOSE IN THE CASE... If they are not there, and the bearing spins - Kiss it good bye, All of it.
I have the pins- 50 cents each and mine are the right length. (pins must be 8.0MM and no longer, else they will protrude into the bearing and wipe it out as soon as you torque the case up..