this is a good time to do a body lift if you have any interest... it makes getting to the exhaust manifolds SOOO much easier.

There has been a lot of argument over whether or not this is an interference engine - with the general consensus being yes - but I wouldn't be terribly surprised if it isn't after all...

So what do you think would cause the valve leaking you're seeing if not a piston collision? Poor machining/seating in the first place? Head warpage?

By the way, if you can snap some pictures of the heads, pistons etc while you have it all apart it would be really interesting to see them.