From F.5 on, the oiling is different. So, someone with a '73 engine typically sees an oil pressure drop as it heats up, and the oil pressure goes up on a 2F when the engine gets to temperature. The F doesn't waste much oil pressure on running it thru a cold filter, it is bifurcated and it easily flows thru the engine, all leftover pressure is for filtering. The 2F must pump all its oil thru a fine fine fine media, which is very difficult at startup or when the oil is too viscous, after it gets warm, it has more oil going thru, and therefore more oil pressure where it is read by the sender unit.
My suggestion is to install a Denso filter on the engine in question, just to be on the same page as more of us, and because the Wix has a bad reputation on forum threads, and because it is not expensive and easy to do without changing the oil. I wouldn't toss it, just wipe it down, and cover it with plastic wrap to keep dust off of it stored with the threads up, if you want to see how it affects things. Most people that I've encountered suggests that your choice of filter doesn't affect oil pressure, but, it seemed to make my needle lean right. There are huge differences in the medias and internal volumes of these filters, so it makes sense to me, plus they all have some kind of pressure release valve psi rating, but the info is largely hidden.
My suggestion is to install a Denso filter on the engine in question, just to be on the same page as more of us, and because the Wix has a bad reputation on forum threads, and because it is not expensive and easy to do without changing the oil. I wouldn't toss it, just wipe it down, and cover it with plastic wrap to keep dust off of it stored with the threads up, if you want to see how it affects things. Most people that I've encountered suggests that your choice of filter doesn't affect oil pressure, but, it seemed to make my needle lean right. There are huge differences in the medias and internal volumes of these filters, so it makes sense to me, plus they all have some kind of pressure release valve psi rating, but the info is largely hidden.