Originally posted by camaroracer16
even tho they are different sizes? the holes arent gonna change how the motor runs or anything wil it?
Yep, They were cast into the block when it was pored into the mould. They just allow the oil to run back to the pan. You can clean the cast hole up to allow the oil to flow back better. ONLY IF YOU ARE REBUILDING THE ENGINE tho. Don't grind on the block unless ALL the filings can be flushed out like a "bare block" before cleaning and assembly. It's worked just the way it is til now.