6BT5.9 Cummins Exhaust Valve 4994143 Parts Catalog Ref No. Part Name Part No. Required 　 Cylinder Head 3977600 1 　 Cylinder Head 3966452 1 1 Cylinder Head 3966451 1 2 Expansion Plug 3812092 5 3 Hexagon Flange Head Cap Screw 3920780 14 4 Valve Spring 3926700 6 5 Valve Collet 3900250 24 6 Intake Valve 4995554 6 7 Exhaust Valve …