The DC head should be RE-TORQUED after the engine is brought up to operating Temperature. Back off ONE bolt at a time and re-torqued following the sequence from the inner bolts to the oouter bolts. Almost all older case motors require re-torque of head bolts.
Second thing for the rockers, loosen the hold-down bolts and turn the main tube until "appropriate" oil flow. Too much flow leaves lower oil pressure for everything else. Remember the CC's only required oiling before working the motor. I usually keep a pretty slow steady flow of oil.
Hope this helps.