On this engine is is RARE for a lifter to fail. If one of the oil rail retainers is broken, it may have starved for oil at some time. If this happens, the rockers will fail. Have the rockers checked and replaced if needed.
1991 GMC Syclone
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM