Good Deal, Decent Deal or Bad Deal?

The places I have seen 340s crack most often is in the lifter valley, and across the side of the block. Of course, you'll want to check for excessive ridge, and see what the bore is. If it's been bored before, and needs it again, I don't think I'd be too interested in it.

$1000 seems kind of high right now, but that could change depending on what the other parts are, and what "fresh" heads mean. A lot of "fresh" heads were touched up, and then run hard for 50,000 miles. Not too fresh.

It could be a decent deal, and it could be way too much. Be skeptical. Don't go there expecting wonderful things, or already deciding to buy it. Emotions shouldn't be involved. And like others have said, a lot of times someone claiming to know nothing is really just playing dumb, hoping to catch a sucker.