360 block cylinder wall thickness

I know this question has been asked many times within post but has never really been answered.
Over all what is a minimum wall thickness should I look for when rebuilding a block. I know this all varies from intended use.
So I know there are some builders on this forum that can enlighten the masses with general guidelines per style of build.
As for me I plan on building a 550 to 600 block hp 414ci , so when I go to my machine shop I would like to know when he tells me that so and so cylinder ran a sonic test of .150" I know it is either good or bad.... thanks all