SERVICE MANUAL VALVE TRAIN - CAMSHAFT, TAPPETS & PUSH RODS Section 4 II. Increased    Cam    Lobe    Width    and    Forging Diameter To   accommodate   the   increased   diameter   tappet   the camshaft  with  19.05  mm  (0.75  in.)  wide  cam  lobe  and 36.58 mm (1.44 in.) forging diameter has been released into  production  and  service  replacing  the  old  camshaft with  76.26  mm  (0.64  in.)  wide  cam  lobe  and  30.99  mm (1.22 in.) forging diameter.  [Refer to Figure 6]. IMPORTANT:  Both New Camshaft (IH P/N 1 802 337 C1) and Displaced Camshaft (IH P/N 691 488 C1) have the revised intake ramp height providing a common intake and exhaust valve lash of 0.64 mm (0.025 in.) Engines built with and after the following serial numbers incorporate the new style tappets and crankcase: ENGINES SERIAL NUMBER D-414 Not Yet Available D-436 Not Yet Available D-466 Not Yet Available DT-414B 155805 DT-436B 121623 DT-466B 140086 DT-466C 400001 Engines built with and after the following serial numbers incorporate the new style camshaft: ENGINE SERIAL NUMBER D-414 Not Yet Available D-436 Not Yet Available D-466 Not Yet Available DT-414B 156104 DT-436B 121816 DT-466B 140841 DT-466C 400001 Figure 7.  - Tappet Identification The following is a list of acceptable combinations of camshafts, crankcases and tappets: OLD STYLE NEW STYLE OLD STYLE NEW STYLE OLD STYLE NEW STYLE CAMSHAFT CAMSHAFT CRANKCASE CRANKCASE TAPPET TAPPET X X X X X X X X X X X X CGES-185-3 PRINTED IN UNITED STATES OF AMERICA Page 4