does any one have pics of there cylinders with the heads off. I have an lb7 with something wired i think, it has like three rows of little round spots around the top 1"to 2" of the cylinder they are the hole way around they are about the size of half a penny. any ideas would help with what this might be. they are on the passenger front teo, didnt look at the rest but this looks funny. the cylinders also have like a dark line in them about an 1" long and are at they same spot on the wall about 1/2" from the top if anyone has any picts of theirs or know what this is let me know. motor has about 180,000 on it:confused:

sometimes reffered to as "leopord spotting". Normal

I pulled this from a GM bulliten that shows engine failures due to aftermarket "power up" devices. The leopard spotting in the top is normal. The polished off cross-hatching is not.

Directly from the bulliten : Important: Cylinder Wall Spotting (commonly referred to leopard spots) is from the induction hardening process of the top 1/3 of the cylinder wall. This is normal for the Duramax ™ Diesel.

Ding ding we have a winner. ^^^^ is correct!

thanks so no worries about that, but is the hair like line towards the back of the cylinders(on pass side) at like the 8 to 9 o'clock position when looking at them from the pass side. didn't look at drivers side yet!

Post a pic and someone should be able to help

ahhhh, so that's what those spots are :)