There's a recent and very informative discussion of good engines for 960's at
http://www.brickboard.com/RWD/index.htm?id=940932

There have been lots of problems with the earlier 6-cyl engines.

The most recent posts in that thread indicate
1995 and later 6-cyls were more reliable than the earlier ones.

Now I think we know why there were few responses to the original post.
Probably would be a nice car with a '95+ motor dropped in.