Tried new plugs?
If replacing your plugs solves your problem, try to see what caused the plugs to foul in the first place.
have a competent tech check it out!
1939 170 - till I was 3, still turns heads
1989 300TE - daily driver has 263k
1987 300E - purrs happily with 120k
1983 300SD - keeps my friend happy