[Captnf]

1997 SBC 350 cylinder # 1 Is this a result of piston slap or overheating etc. It is going to the machine shop, is this something they will be able to take care of with a .030 bore.

 

[ericnova72]

You talking about the spot of no top ring contact right at the most outboard location at the top of ring travel? Likely just heat and age and the casting "shrunk", that is below the spark plug and exhaust valve hot spot in the head. The block casting is somewhat green and not aged when it is first machined, everything moves a stabilizes with use and then the casting is considered "seasoned" and more stable.
Or the llack smudge?
Or the vertical scratches in the bore?

Overbore will fix it all, have it done with a torque plate if you want to really have the bore round with the heads bolted on.

 

[Captnf]

Thanks for the reply ericnova72, yes I was looking at the bullseye looking circular marking.