Just as a candidate for an LS-swap Sleeper, if it's super nice, $3,000 should sell it right away.
For that matter, an inexpensive SBC swap could net someone a nice highway cruiser and solve any Diesel issues.
Might have to do something with the fuel system, at least flush it ?
To someone who's not worried about the GM passenger-car Diesel thing, I would think a super clean one with no problems might pull $4,500...but might take a while.