Originally Posted by Shmoo
You will need to tap for oil unless you want the oil pressure idiot light to be on indefinitely. Unless you care, just pull the stock sender off and replace with the aftermarket one.
Not nesc, you can always tee off of the idiot light and have the idiot light on one port and the oil pressure sensor line off the other running to the gauge.
Although this isnt recommend typically, because if something breaks then you lose oilpressure = bad.
EDIT: Excuse me, im an idiot, didnt check out the attached diagram above.
The one of the smarter version with a line running to the tee to accodate for engine torque.