Did a search could not find an answer so forgive me for asking if this was asked already. What should the oil pressure be on the 2.8 L? On my '97 Tahoe 5.7 L it's like at 60 psi on my '85 2.8 L Blazer it's at about 10 psi, that don't seem right?

 

From what I could find "Google Wise" should be around 40 ish.
Have you verified this oil pressure?

 

Depends on the conditions. 10psi is on the low side should not be a problem if at idle, fully warmed up. You should see around a 10psi per 1000RPM over idle. So 20psi @ 1500-2000RPM, 30psi @ 2500-3000RPM. Comparing to another vehicle is really not valid. No two vehicles will have identical oil pressure as it depends on the fit of all of the parts in the engine, the accuracy of the factory gauge, and the age/health of the motor. Even new vehicles can have differing oil pressure readings by as much as 10psi.