What I’m saying is you will learn more by taking it a machine shop, and having him check the bore with a dial bore gage. In front of you, dial bore gage is the most accurate way to check it. Unless you have one, your wasting your time in what ever method you plan on using it to Measure the block cylinders. The ridge is not an issue, it will definitely need boring. Once you follow that procedure you will learn a ton.
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