I looking for a place to put the oil pressure sender for an Auto Meter gauge that I bought and I'd like to know if Ford's oil pressure switch is measuring pressure before or after the oil filter? I was looking closely at the oil filter adapter today and from what I can tell, its taking a reading from the oil going into the engine since the switch seems to be mounted right in the center of that adapter but I'm not 100% sure.

The reason I'm wondering is because I can mount the sender on my Amsoil dual by-pass and get a reading after the filter but I would much rather get a reading right before the oil goes into the engine. Thanks in advance!