Mornin' Folks!

Not sure if I'm posting this in the right section but if it's not, I ask that the site moderator/administrator please correct it.

Last month I purchased digital,backlit gauges from Glowshift; volts, water temperature and oil pressure.

The installation was in my son's 2005 Cavalier, 2.2 DOHC, automatic. Volts and water temp were fairly simple even though there is NO
room to even wiggle a finger in the engine bay! When it came to the oil pressure sending unit installation, I followed the lead of a few guys who have already been there and done that. I removed a threaded test port from the cylinder head and machined an adapter of my own (M12x1.75 thread pitch to 1/8"-27 npt) had a high pressure hydraulic hose assembly made up and threaded that into the head and the sending unit into the female thread of the hose assembly.I mounted the sending unit remotely to a convenient bracket directly below the brake cylinder. here are some pics of how it looks...









All in all, I was satisfied with the end results except for one thing...the GM specs state that oil pressure should be 50-80 psi @ 1k rpm.

My pressure gauge reads 20 psi @ 600 rpm and up to about 40 psi @ 2,200 rpm(in drive, on the highway.)
I spoke to Glowshift's tech people and they suggested that I change the sending unit due to the possibility of it being bad.Did that -no change. It occurred to me that oil pressure up in the area of the head where I took off with the hose assembly is not as high as the pressure at the factory oil pressure gauge port which is close proximity to the oil pump.

So,here's my question: Has anyone here done this install the way I have and are the results in low oil pressure the same as mine?
I would appreciate any answers to my question. Sorry for the long-winded recital but I wanted to be clear about what I did and how I went about it...I hope I was!

Thanks for lookin', Folks!

Best Regards,

Tony