Mangled spark plug electrode in 292

[Canada20]

Hey all. Has anyone encountered a mangled electrode in their engine before?

It's a rebuilt-to-stock '69 292 I-6 so I don't think there should be any trouble from the pistons. When I got the truck a couple of years ago, it was blowing steam out the tailpipe like crazy and when I had a chance to remove the plugs and have a look, plug 6 was bent. I remember reading somewhere that it's possible for valve guides to wear badly enough to allow enough movement for a valve to connect with a sparkplug and that may explain the steam. I kinda doubt the head was ever converted for use with unleaded gas......

Just trying to get a handle on what to expect.

Thanks

Greg