Maybe a week ago or so I wrote 'bout my problem - low oil pressure in 2.9 EFI. It did not go higher than 2.5 atm, when it should be somewhere between 3 & 4 ATM at 2000 RPM. Anyway, I opened the oil pan and took off the covers from main and rod bearings. Initially I was aimed to change MAIN bearings, but was very surprised to see, that they look OK - the surface is matt "alluminum" color, no scratches or evident surface defects. When I opened rod bearing covers and took a glance at the bearings - WOW! They're dead. Lots of scratches, the surface has "copper" color in some spots. Now I try to figure out how could that happen. As far as I understand main bearings are more likely to wear off. What do you guys think? Maybe previous owner already swapped main bearings? (unfortunately I can't contact him)
Another question is: do rod bearings affect oil pressure drastically? If I swap only them, will this significantly increase oil pressure?
I rely on your clever advise, Comrades

PS Forgive my English - I'm from Russia