Does this 5.9 Magnum look ok?

magnummopar said
The tabs are called tattle tails and are epoxied to heads/engine so they can tell if you overheated the engine. They say LKQ on them, a nationwide wrecking yard....it was a used engine sold by them. The #8 piston is horribly carbon fouled which could mean bad guide seals or rings but based on the amount of oil, I would guess it had a bad belly pan gasket, allowing vacuum to suck oil into intake annd pool in rear of pan. There appears to be some form of detonation on that cylinder from carbon turning into a briquette stuck to cylinder. If the big one is carbon, scrape it off, if its aluminum, use dremel to sand it flat. Might want to pull that one and look for cracks in piston and oil below rings. With that much detonation, you might have a broken ring as well. Other than that, it doesnt look out of ordinary at all

Evan I think what you are seeing there is a result of low compression in that cylinder due to this spot in the gasket area.
It also looks like at one point there was something that got in that cylinder because of the little dents in the head and piston top.
The low compression from that leak in the gasket could certainly cause a lot of carbon buildup (like on that plug in the that cylinder and the piston top and valves.
Sorry, but I have to disagree on the detonation theory and go with low compression and low burn heat causing it.
It also looks like the other cylinders were right behind it to do the same thing if you look at those area's on the other cylinders.

Also look at the valves on the cylinder where the gasket is in the best condition.
That set looks better than the others, and so does the gasket area compared to the other cylinders.

And to the OP, those scratches I see are called cross hatches and are from the machining of the cylinders.
Seeing those is a good thing because it tells you that there isn't a lot of bore wear (usually ring wear either)