2B20:3 is 62/Feb/20th/3rd shift. Well it's sure worth checking the wall cores. You never know. This link shows a 2 bolt main 427 industrial block. You can see the three crossbolt bosses on each side opposite the sides of the 3 center maincaps.
http://www.ford428.com/427c7aea/

Your block would look like that if it had the crossbolt bosses.

G.