ok, my all time favorite car is the 1970’s 240z from Nissan. I found this video tonight where some guy put a mercedes diesel dohc engine (om606) into an old Z. http://www.youtube.com/watch?v=4RghY0For0Q
I also found where an LD28 diesel motor out of a Nissan Maxima was swapped in. http://www.youtube.com/watch?NR=1&feature=fvwp&v=wLbN45c44Q8
sorry that the last one has bad audio (it bugs me too)
Maybe someday i will buy a Z and swap in a small powerful direct injection diesel. I can only dream.