Engine Clanking -WTF!!!

[Goat Blower]

See if you can check the height of the top of the piston in cylinder 1 in relation to cylinder 4 with both at TDC. Stick two equal length pencils or somethign in there and measure the tops. Unless there something in there like a broken valve stem, there's not much that could do that to your spark plug. Hopefully it's nothing. I might be able to drop by later tomorrow night if you need an extra set of eyes.