For 1990-2009 cars only
Important: There is only one production standard piston grade size. When using production standard grade size pistons in all eight cylinder bores, a J is metal stamped in a single place on the cylinder block oil pan rail (1).
A 0.13 mm (0.005 in) oversize production piston is available for in a plant rework of cylinders that do not meet the production standard specification. An S metal stamped on the pan rail (2) next to any reworked cylinder identifies that cylinder as production oversize. A J will also be metal stamped in a single place on the oil pan rail to represent that all remaining cylinders are production standard. All service oversize pistons are the same weight as production pistons. Using service oversize pistons will not affect engine balance.