How far can you bore a 360 safely?

Rumble's right. Sonic test it before you bore it .060 over. I have an early 360 block. You know the one that's supposed to be a thick wall block as alot of people claim. Well it does weigh 4 lbs. more than a 79 block I have setting here so there is some more material somewhere. Well I had it sonic tested and found one side was plenty thick enough on the major thrust side of the cylinders to be bored .060 but the other side would have been pushing it to the limit. This was due to some core shift which made one side of the block's major thrust side better and the other worse. If my old "heavy" wall block wasn't even safe going .060 over not many others are I bet.