ARMY TM 9-2815-256-24 AIR FORCE TO 38G1-96-2 MARINE CORPS TM 2815-24/5 b. Intake valve recess should be 0.024 to 0.044 inch (0.61 to 1.11 mm) with a maximum recess limit of 0.064 inch (1.63 mm).  Exhaust valve recess should be 0.048 to 0.068 inch (1.22 to 1.72 mm) with a maximum recess limit of 0.089 inch (2.26 mm). c. If measurement exceeds maximum limit, install either new valves or inserts, or both to obtain proper valve recess.  Grind valve seat inserts as required, refer to paragraph 3-34.4. 3-34.3. Disassembly. Warning Block cylinder head (2, FIGURE 3-119) using a solid block of wood at each end of head for support while using spring compressor to avoid personal injury. Warning Do not stand in front of valve springs while compressing them to avoid personal injury. NOTE Make  preliminary  inspection  of  cylinder  head  and  valve  assembly  during  disassembly,  looking  for following: (1) Scored Valve Stems (2) Burned, Pitted, or Worn Valves and Seats (3) Loose Valve Seat Inserts (4) Defective Valve Rotators (5) Worn Valve Guides (6) Cracked Cylinder Head a. Using valve spring compressor, compress valve spring (6) far enough to remove valve spring locks (4). b. Release spring (6) tension and remove valve rotator (5) and valve spring (6). c. Remove valve (7 or 8) from cylinder head. NOTE Identify  all  parts  for  correct  reassembly.    Use  a  valve  board  or  other  suitable  means  of  keeping valves in order. d.    Remove valve stem seal (9) from valve guide tower. e. Repeat steps a through d for remaining eleven valves (7 and 8). 3-148