Oil Pressure Gauge

Hey guys,
'85 camaro 5spd 2.8L mpfi 135k with 88k on motor. Oil pressure guage never functioned properly since owning the car. I've put maybe 1k on it since owning. When the car starts it goes up as far as it can until it hits the top peg. If the car is about to stall or rpms drop for whatever reason it will respond and start dropping so i know its registering something. It even did it on the old motor with old oil pump. (newer used motor came with one on it). I've read through the haynes and chilton but they don't say much about it. I have a aftermarket oil press gauge my pops bought for his 79 bird that he never used. when i put this motor in i never saw an line for a mechanical gauge so i'm assuming it's reading it through a sensor??
How do i go about getting an oil pressure reading?
-Thanks

you will have to "T" it in between the factory sensor usually located near the oil filter or atthe back of the intake not sure on the v6 mine is at the back of the intake your Haynes / Chilton manuals should tell you ware to look you can get the "T" at a hardware store

Had the same problem with my '90 3.8 EFI. Pressure read normal at a stop in park or in gear, but when accellerating from a light it would jump past the end of the gauge.

I knew there was no way the oil pressure was this high. Changing the $12 sensor near the oil filter during an oil change promptly resolved the issue.