Are all 340 blocks the same?

Look at:
- How much it has been bored; it's important to find one that is minimal if you are going to keep it for a while so that you can re-bore it.
- Look at the lifter bores for wear and bad rust
- If you want to run hydraulic rollers, then look at the chamfers at the tops of the lifter bores; they can be problematic for hydraulic rollers if they are chamfered a lot (and some are. It seems like some drunk at the end of the machining line did these chamfers to random depths LOL. Or just go to a solid roller. There are several threads here about this issue.