Read post # 12 again, if an exhaust seat is missing, that explains where the Metal shrapnel came from.
It is common for debris in an engine to move from cylinder to cylinder.
I don't know how I missed #12 last night, but that sounds like a good theory. I think the #7 exhaust valve (really all valves) will need some attention.
The engine's got about 3,000 miles after a rebuild. The previous owner had a shop rebuild it just before I bought it. Maybe they replaced the stock seats with hardened steel seats??
So, obviously the heads need to be gone through, but I'm wondering exactly what to do about the cylinders. I was hoping I wouldn't have to do this, but I'm thinking the pistons need to come out. Do you guys think I need to pull the block and have the cylinders machined? The walls are pretty smooth, can still see the hashmarks from being bored, but you can also barely see (and feel) tiny tiny pits from those dang pieces of steel.
[Edit]
RustyRatRod - I didn't see your comment until just now about having the cylinder bored. Gosh dangit!!! Oh well, gotta do it right...
