If you really, really need an engine, get a recently wrecked car or something that is rusting out. You'll get a bunch of extra parts or can sell the parts to pay for the engine. I bought an entire running car with an engine for $600 at 200K miles. As has been stated here, you're in for a ton of money on a rebuilt, so if you can get a good used one, you should.

These engines were extremely well built. Figure out exactly what is wrong with it before you conclude you need a rebuild. There are lots of stories on this forum about people buying good cars for super cheap because the last few mechanics couldn't figure it out.

Dkr.