I recently drove a auto defender off road and could not believe how nice it was. I have a few questions to add.

How does the length of the disco trans/transfer case compare to the series truck? If its longer things may get real tight with the merc 5 cylinder. What sort of revs will a stock D1 motor turn at 100mph? It may be out of the usable range of some of the diesels but I'm not sure. I'll be real interested in what you find. There are more and more people interested in doing this sort of thing I feel (me included)