The W114 Mercedes-Benz 240D is an abysmally slow car. I should know...because I owned/drove one back in the 1990s. It still had a sense of purpose and aristocratic provenance..but it was slower than a one legged tortoise on horse tranquilizers. It is, however, common to swap something with more power into the old chassis...but I guess the 22R would not have been my first choice, which isn't to say it is a bad idea at all. Find this
1975 Mercedes-Benz 240D with Toyota 22R offered for $3950 in Mission Beach, CA via craigslist.
Tip from Rock On!