Standard bore, note the photo of the mains area under the bearing, re. All the oiling work has been done to spin it and not starve the rest main (something theses blocks were notorious for). I have the tools to tap the frost plugs into the screw in type (+ I have one set of them left) for an additional fee. I’m in Victoria (Not on list of cities usedvic offered so ad says Vancouver) and can ship it over, but the fee is on you.