What is a healthy engine oil pressure? and how many quarts will i need to change my oil?

 

Don't have the owner's manual, eh? The rule of thumb is you need 10 psi of pressure for each 1,000 engine rpm. Most Blazers will show from 20-60psi depending on rpm's.
The book says 4.5 quarts, but most will hold up to 5 quarts.

 

Exactly!

 

so the gage in the dash is the oil pressure right? or is it the temp?
yeah my manual has gone missing.
I really have neglected my blazer while i have been doing body work my 93 s10.

 

Well, I can't see your dash from here , but mine has both oil and temperature gauges in it. They are identified by the icons beside them.