340 .040 Bore Okay?

Before sonic testing became avail, I built a few 0.060 over 340s, and after refreshing a few, I did notice one cylinder had a "funny/different" wear pattern on the wall.
Later, upon reflection, I concluded that was the cyl wall "flexing" , and scrutinized future cyl walls closely.
That was 60 over - the # matching motor in my Dart is 60 over, ran 12.5 pistons for years, refreshed a few times, no cyl wall distortion when inspected .
Still running well today !