[CHP2RA]

Gary, Ed, Don, Chanmad & FWB,

You were correct as to what caused my #5 exhaust valve to drop. The underside of the rocker arms (other than the rollers) on all valves were contacting the valve spring retainers. The underside of the rocker arm on the front left #5 cylinder exhaust valve was also contacting the valve stem head all around the roller, but perhaps that was after the valve dropped. The off-center contact likely caused the keepers to move in & out of the retainers, wearing the lands, causing them to release the valve stem.