From what I was able to find out the Toyota Hemi was produced from 1970 to 1982. The displacements were 3.4L (207 CI) and 3.8L (231 CI) made 170-200 HP respectively and weighed approximatly 250 pounds (all aluminum).

There's a bit of a write up on them in Tex Smiths Hemi Engine manual.

I actually saw one of these go on E Bay once a couple of years ago, but you could be in for a LONG search.