I thought this was kind of interesting, this guy swapped in a LD28 (diesel) into this 280z. I wonder how the performance compares to that of a stock l28 that the car originally had?

http://cgi.ebay.com/ebaymotors/DATSUN-Diesel-powered-280-Z_W0QQitemZ150133674135QQihZ005QQcategoryZ6187QQrdZ1QQcmdZViewItem

Guy claims it's the only 280Z running an LD28. Maybe so, but it's nothing new for the S30 chassis. Here's one among several:

That's my friend Keith's car. I've ridden in it and can vouch for it, it'll scoot. It doesn't sound like a Z, and by that I mean the exhaust note is quite different, but the performance is good.

He claims that he gets 40-45 MPG on the highway.