Cummins Engine Parts used for K19, K38, K50, NTA855, 6BT5, M11, QSL9, 6CT8.3, QST30, QSK60, QSK23, QSK15, VTA28, L10, ISB, ISDe 1. Have a competitive price2. Excellent in quality3. Original Cummins engine parts4. Suppiled directly by manufacturers5. Manufactured by DCEC, CCEC, XCEC6. OEM standard7. US products also provided follow your request Cummins QSL9 5259423 cylinder head