Sorry, but ain't buyin all that. Based on water displacement, I run a 3/4 fill block. Never seen a "line of demarcation" on the cylinder walls. Never had any piston scuffing issues. With the temps we usually run ( under 200 degrees ) don't think there is a lot of thermal expansion / contraction to worry about. If there is any, it would all be on the expansion side, so don't see it scuffing piston walls. On wall thickness, I have run small block motors all out of E58 coded cars. Supposed to be "hand picked blocks", what ever that means. Had two sonic tested. All at .2 or thicker walls ( before boring ). Don't know if those two items are related, but just eyeballing lifter bore holes and castings in the lifter bore areas, looks like minimal core shift on these blocks.