Ever Since i bought my 1989 5.0 LX it has burned oil. It burns one quart every 500 miles (roughly). My mechanic said it was the O-rings because i only see blue smoke when i get into high RPM'S. I also heard on this forum that it is an easy fix if its the valve guide seals. To replace an O-rings i heard would be 1000$ because they need to take apart the engine. I was wondering how i can tell if my oil burning problem is from valve seal leaks or o-rings? is there an easy way? will a compression test tell me? or do they have to take off the valve covers? Any help would be appreciated. Thanks a lot.