TM  10-3930-643-34 ENGINE,  FUEL,  EXHAUST  AND  COOLING  TROUBLESHOOTING  AND  MAINTENANCE.  (cont) 4-4. Cylinder Head Assembly with Valves. (Sheet 16 of 18) INSTALLATION  (cont) 67. Using a 1/2” drive torque wrench, tighten bolts (4) to 110 lb-ft following sequence A. 68. Check two end rocker arms for freedom of motion. 69. Tighten bolts (4) to 155 lb-ft following  sequence  A. 70. Tighten bolts (4) in rows to 165 lb-ft following sequence B. NOTE Return  vehicle  to  original equipment  condition. 71. Operate engine under load for at least one hour, refer to TM 10-3930- 643-10. 72. Retighten  cylinder  head  bolts  accord- ing to procedure given in step 69. Go to sheet 17 4-44