Steve,
Don't Panic!
Whilst you could, no doubt, pay $11K for a new engine, there's absolutely no need so to do! There are lots of other options that will cost you far, far less, such as getting a donor engine from a contemporary sedan. That said, if you just want to sell the car, you'll need to provide a lot more info and post pics. Lots of pics.
May be worth investigating the replacement engine a bit more first though.
Good luck.
JH