What clean burning Toyota diesel do you speak of?
The only Toyota diesel truck engine really is the 4.5L single/double turbo V8.
Other than that, it's Hino engines or put a Cummins in it.
yes, Cummins 5.0
http://blog.caranddriver.com/toyota-tundra-does-a-titan-move-turns-to-cummins-for-a-diesel-v-8/
LR is not a good comparison mainly due to economies of scale, demographic, and the design intention and goals of the LC platform as designated by both Toyota as well as the chief engineer Sadiyoshi Koyari.
Actually LR is a good comparison. While I can't reveal sources, I can say that I have contacts at both Toyota and LR and they reference each other quite a bit. For the past 18 months I've spoken personally with engineers and the dir of mktg at LR specifically about Land Cruiser. Overseas, their market segments overlap quite a bit more than they do here in the States.