You do not need a V8 engine?
You do not need an oil filter?
As posted above,
"You'll need a T-fitting in the oil-pressure line location."You put a brass T-joint into the block where the original oil-pressure line goes into the block. You screw the male end of the T into the block; and, you screw the oil-sender line into one female side of the T (an adapter might be needed), and you screw the pressure switch into the other female side of the T (an adapter might be needed).
NAPA can provide any brass fitting made by Weatherhead-Eaton. You'll have to
check their catalog for a T-fitting that will work in your situation (trial and error will most likely be needed, perhaps for the end on your existing oil-pressure sender/line). The diameter of the hole in your block is measurable, and the diameter of the pressure switch should be given on the NAPA site.