GM sportsman Bow Tie sbc block question

[prostockpete1]

late 90.s GM Bow Tie Sportsman sbc block question .. engine still in car how do I tell if it is a 1 or 2 piece rear seal .. i see the aluminum seal plate behind the crank flange in photos of BowTie blocks in GM catalog but no other data telling me if a 1 or 2 piece without disassembly .. has typical 6 bolt crank flange .. thanks