360 stroker, cylinder wall thickness

That's why I call them all "myths". The factory's intent was to have some thicker for certain reasons (cold weather 400 blocks...) and some people guess because the casting was similar that it must be the case that some are thicker. With the "230" 400 blocks the casting quality hurt the resulting block castings. And on the 360s I'd wager that the first few 360 blocks were thicker because they used the 340 block cores... Right up until the QC guys figured out why the base iron was getting used up faster than they expected. Then it get cut back - but the myth was born.