The spigot on the new cover is designed to read the pressure on the inside (filtered side) of the filter.
With the spigot machined flat and a groove in the cover, the guage will only read the oil pressure ahead of the filter. If the filter plugs and reduces pressure/flow to the engine, the guage will still read the oil pump pressure on the outside of the filter.
"We'll burn that bridge when we get to it"
Deadhorse- 2002, 2012
ALCAN 5000- 2004