I searched but came up dry. I just bought a very very nice 1977 240d 4 Speed. It needs an engine however. I found an 1981 240d 4 speed and am wondering if this is a plug and play swap? I will buy the 81 if it is. Wikipedia says the horsepower is different however im unsure if thats just an internal adjustment or if its a completely different engine altogether. So please mercedes gods tell me if I can or cannot do this easily.