Its only desirable to the right person
Lots of guys absolutely detest them, but other guys (mostly 4x4er's) love em, esspecially with a turbo kit on them.
Personally, I wouldn't mind one
Just can't run em like a gasser engine, or you blow headgaskets and stuff, lol
2wd chassis isn't worth too terribly much, couple hundred for the rear diff maybe, and the SM465 is pretty common as well, 50 - 100 bucks is typical.