New oil pressure switch doesn’t fit...318 LA
I know this is a mess,
I also have a 1/8" NPT oil sending unit hole jacked up on a 4cyl flathead.
I asked the machine shop to remove the remnants of a broken sending unit.
After all the machine work was done, fresh .080 overbore, took the engine block home.
The broken sending unit was still in the block, went back to the machine shop and a new guy removed it, than while I was standing there ran a tap into the block way too deep.
To this day I have a slight weep from the oil sending unit, the NPT threads bottom out.
NPT threads only have so much taper for sealing.
I should have just removed the broken piece of brass myself.