Tell me the story of the life of these pistons
 

This is what the pistons look like out of a salvage yard 2008 66,000 mile 6.0L engine I recently purchased. Would you say the carbon/ coking between the ring lands and oil rings came from not changing the oil or overheating?
https://cimg3.ibsrv.net/gimg/www.per...d1b18c7a6d.jpg

https://cimg5.ibsrv.net/gimg/www.per...1020e9c74f.jpg

Are you 100% sure it was a 66k Motor?

Not enough oil changes.

Nope! Ebay buy. Had pictures of the 2008 3500 Savanna donor vehicle with the engine in it along with the dash mileage shown. I do know it is a gen4 engine that would be in that vehicle. The cylinders are a bit glazed and only cylinder 6 shows wear that I can feel a lip. The good thing is the crank, rod and main bearings look like new. The block is at the machine shop getting cleaned and bored.

I'm with FFDP.

Those 3500 Savana vans are used mostly as service vehicles. Some companies do a good job of servicing them, others do not.

1. Not enough oil changes (as FFDP said)

2. They lied to you about the mileage.

Either way, that's going to require some cleanup.

The rest of the engine just has a smooth caramel color. The pistons are the only ugly gunked up parts. I'm getting new .030" over sized pistons for the newly bored cylinders.

My goodness! I've never seen pistons that gummed up. My first thought was that it had been submerged or was being driven around with a blown head gasket.