The oil galley core plugs need to be removed in order to properly clean and rebuild. Engine block has dead ends in oil supply ports.
Remove plugs, wire and clean ports , install new plugs.
Tools are made to install plugs at proper depth in block
The tool set is made from O1 tool steel for a lifetime of use.
1- 10mm (rear engine)
1- 16mm (bell housing side)
1- 16mm (serp belt side)