ARMY TM 9-2805-257-14 AIR  FORCE  TO  38G2-103-2 NAVY NAVFAC P-8-612-14E Table 5-2. Engine Repair and Replacements Limits. Item VALVES Intake  and  Exhaust Length to gage point Stem diameter Head diameter Seat  angle Stem  to  guide  clear Clearance  valve  to  lift Intake Length Stem diameter Head diameter Seat  angle Stem  to  guide  clear Clearance  valve  to  lift VALVE SPRINGS Length  (valve  open) Pounds load (valves open) Length  (valve  closed) Pounds load (valve closed) VALVE GUIDE Exhaust  and  Intake Inside  diameter Measurements Minimum 2.7885 (7.0827) 0.3100 (0.7874) 0.8390 (2.1310) 45° 45’ 0.0020 (0.0050) 0.0040 (0.0101) 2.7885 (7.0827) 0.3100 (0.7874) 0.8390 (2.1310) 45° 45’ 0.0020 (0.0050) 0.0040 (0.0101) 0.880 (2.2352) 42 (19051.20 grams) 1.095 (2.7813) 1 0 (8618.4) 0.3125 (0.7937) Maximum 2.7935 (7.0954) 0.3105 (0.7876) 0.8490 (0.2156) 46° 0’ 0.0035 (0.0088) 0.0070 (0.0177) 2.7935 (7.0954) 0.3105 (0.7876) 0.8490 (0.2156) 46° 0’ 0.0035 (0.0088) 0.0070 (0.0177) 0.880 (0.2352) 46 (20865.60 grams) 1.095 (2.7813) 21 (9525.6) 0.3135 (0.7962) 5-58