Vorshlag developed this LS V8 block off plate kit to cover the oil pressure feed port in the block of LS1/2/3/6 wet sump and LS7/LS3 dry pump engines. We make these on our in-house CNC machine from .125" thick 6061-T6 aluminum, and include stainless button head bolts to secure it.
This port above on the block needs to be blocked off if you are moving the internal oil pump from an LS engine and going to an external dry sump pump. Check with your engine builder if you are unsure, but this only applies to oiling systems that are purely external pumps, not some of these hybrid "dry sump" setups that use one internal pump and an external scavenge pumps.
The first step is to add some RTV sealant around the hole marked in the first picture. We used the grey RTV here.
While this RTV is still setting up, install the block off plate, then thread in the 2 stainless M8 fasteners. Torque those to 18 ft-lbs and that's it - you are now ready to delete the internal and move to an external oil pump!