Advice needed on used crate engine

I think 500 bucks for a turn key crate engine is a great deal may not make the power you want but freshen it up drop it in have fun cruising.
Yeah, but it has to have more power than my 340. The pistons are slapping pretty bad, and the rings are shot.
When you get your new engine ready sell it and I'm sure you can get all your money back. Especially if someone can hear it run before you pull it...
I was going to make a short video of it running before I pulled it, showing that there is no antifreeze in the oil and vice versa. It will be sold as a rebuildable core only. I figure the block and the X heads should be worth $500.