Yeah the b15 knuckles are all the same as well as the bearings, only difference being the hub.
As far as the question about the bearing being wider than the b13/b14, I already answered that, Its wider, It wont allow the snap ring to be seated unless you machine down the lip on the inside that the bearing seats against enough to allow the bearing to go into the knuckle enough to get the snap ring back in. You cant not run the snap ring or the bearing could back its way out of the knuckle.
As far as the question about the bearing being wider than the b13/b14, I already answered that, Its wider, It wont allow the snap ring to be seated unless you machine down the lip on the inside that the bearing seats against enough to allow the bearing to go into the knuckle enough to get the snap ring back in. You cant not run the snap ring or the bearing could back its way out of the knuckle.