I am constantly hearing people that want to do a valve job when all that is necessary is VG seals. Well the M110 engine is the exception to the rule. It is a terrible job. It is atleast half the work of a whole valve job. One must remove the cam housing and then approach like other motors.
With 200k pull the head and repalce the guides. The bottom ends are pretty good.
Bosch Master, ASE Master, L1
33 years MB technician