You’re selling 30 over 340 block for $700 with rusty bores. I’ve bought std bore motors with less rust on one side of bore not all over. And it did not fully clean up with 30 overbore.... A seller could: hot tanked it, magnafluxed it, sonic tested, even rough bored that to make sure it rebuildable. Of course most people don’t. And if they do, they ask more money.
So who knows if it’s rebuildable?
[FOR340 block