WATCH THE TIMING CHAIN if it's not had the dual chain retrofit. The
single chain wears really fast, and a valve job is expensive.
Otherwise it's a nice M116 engined W126 -- a bit short on power, but
otherwise very nice.
You shouldn't have any real problems IF the engine has been maintained
properly, although you are approaching cam/valve job age on that
engine, and if the heads have not been off, you will likely have to
send the block out and get steel inserts put in when the head bolts
pull the aluminum out -- very common problem with the early aluminum
blocks. Expensive, too.
Peter