I'm picking up my third oil sensor this weekend. The last two new sensors pegged out at 80 psi and stopped working.
So like you I've done a lot of asking on this board the last couple weeks.
I would agree with ballistx but if it pegs out at 80 under load then returns to 40/50 at idle...sounds like its working fine--I'm jealous.
It could be you (and me)--I've been told if the oil pump flap sticks, it's going to blow sensors. That's a rebuild I'm not ready for yet.
But it COULD be the sensor...you also said it pegs out at 80 at idle also which sounds like a crappy part. If your rubber gasket is seated right between the connectors and clip is sound you should be allright--something to doublecheck.