So my machine shop told me my crank was bad and needed a new one so I bought one from GM. When I dropped the crank off he showed me a blemish in one on my cylinders about the size of a dime that didn't come out with a hone. It a 98 block so not much can be done as far as boring. Do you think it would be ok and the rings would seal or is it junk. I ran my finger over it and could just feel it. I don't know if I should trust it or not.

 

Stock pistons?

What's the current bore size as is?

 

Pistons are stock and bore is stock

 

Well your next option is to bore it out and use an aftermarket piston... Or get a new block, but it just depends what your future goals are too, now might be the time to go forged rods/pistons...