Chevrolet Repair: low compression, gmc sierra, compression test

Question
i have a 1989 gmc sierra with a5.7 350 tpi i lost compression in 2 cylinders and clues as to why . and is there anyway to fix this with out a rebuild thanks

Answer
Hi Joe... depends on if it is a valve or ring problem... do a wet compression test... put a little oil in the cyls.and see if commpression increases if it does chances are it is ring problem in which case you will need a tear down...if no increase could be a valve problem.... hope this helps