it's not that a 347 will break the cylinder walls, but because of rod angles, the potential to wear the walls quicker is higher with a 347, than with a 331. Metallurgy and technology have come a long way, but geometry and physics have been with us from day one...they still trump technology
...but that statement will probably cause a holy war with the 347 owners anyway...
but, the debate between which is better, 331 or 347, is very much a dead horse. the 347 will make more power simply due to more cubes...but people like me will go for the 331 because of personal reasons.
in a nutshell...build what you want, whether it be a 331, 347, or a 355...but if you really want cubes in a windsor package, go with a 351 based stroker...