NTA855 Cummins Cylinder Head 4915442 Parts Catalog Ref No. Part Name Part No. Required 　 Cylinder Head 4915442 3 1 Valve Collet 127554 16 2 Intake Valve 135957 4 3 Exhaust Valve 145701 4 4 Valve Spring Guide 170296 8 5 Valve Spring 211999 8 6 Valve Spring Guide 4913845 8 　 Cylinder Head 4915441 1 7 Valve Insert 127930 …