Cylinder Block

Check each cylinder for wear or damage. Check for cracks in cylinder walls, coolant passages and main bearing insert cavities. If any cracks are found, replace cylinder block. Ensure oil passages are clean. Ensure freeze plugs are in good condition. Check cylinder walls for gouges, pitting or scores deeper than .002" (.05 mm). If any are found, cylinders will have to be bored.

Fig 1: Positioning Piston Ring End Gaps

Courtesy of GENERAL MOTORS CORP.