150mm or 152mm Standard Liners
ISX Engines and Blocks manufactured after 1-1-10 can have either a small bore or large bore diameter block and liners. Cummins states that Quick Serve may not be accurate; verify physically. Measure the OD of the liner at the flange just above the liner packing groove. Small-bore measures 150mm or 5.906" Large bore 152mm or 5.984"

150mm or 152mm Anti-Polishing Ring Liners
ISX Engines Manufactured in 2015 and up incorporate a carbon scraping ring which installs in a counter bore machined into the inside of the top of the liner which overhangs inside the cylinder bore to scrape excess carbon from the pistons above the rings. It is designed to control liner bore polishing from carbon packing on the pistons. Early ISX engines can be upgraded to these new liners and the Low Top Reduced Diameter Top Land Pistons

Piston Identification: Standard High Top Ring Pistons for the Standard Liners, measure 135.3mm diameter and 8mm from piston top to the top ring. Low Top Ring Piston for the Anti-Polishing Liners diameter 134.86mm and 11mm from the piston top to the top ring. Early Two Piece Pistons with aluminum remove for the anti-Polishing Liners, skirt can be upgraded to the New Single Peace Pistons by upgrading the Rods from non drilled to drilled oil passages to the rod bearings.