Pieces of steel in cylinder??

I would not leave any stone unturned here. Knock the plugs out of the rocker shafts and make sure they are free of any debris as well. Make sure you put a brush or mechanic's wire through every single oil galley in that block and make sure they are all clear and clean. Engine brush kits are cheap. That thing has been through a real catastrophic failure. You don't want another one.

Oh and don't forget about the screw in plug in the driver's side galley under the distributor and the press in plug under the rear main cap. Both must be installed !