I have a 4430 with 7000 hrs, doesn`t use a drop of oil. A couple yrs ago the oil pressure gauge developed a "quiver" on the needle, I use it for light duty work and if it had a "idiot light" you`d never know it had a problem. Is the problem perhaps the gauge, given that the motor is tight? I use JD 15-40 oil, change every 60-70 hrs.
Also, I have a truck with a 427 Chevy motor, the oil pressure is good at speed or "cold" but warm and idling it drops to 22lbs, it`s done that for years and been okay. Mechanics that I talk to say "that is normal with that motor". I use the recommended 10w-30 oil. It just seems to me that 22lbs is scary low, but again if it was a idiot light, you`d never know. Thank you.