Is this a good engine for the price

He lives close to me and i talked to him about a year ago,...seems like a decent guy.He had one engine that was well used for around $3500 and the new one with very little time on it at $6500.
These engines make power at high rpm and you would probably want to change the cam for good street performance.He can only tell you what he's been told and there may have been changes before he got the engines..I think the Cascar engines are restricted to 2 bbl carbs.
There are always risks buying anything used.