I find interesting after buying new Cosworth alloy block couple years back iirc next to each other the new one has considerably more meat around head bolt holes running the length from head face down to the threaded part which also much deeper with thicker material around it. On the old cast blocks the threaded area in worse case as in my sods law it cracked through that small amount of material I think sustained high revs rather than power killed that one. The other one had long stud conversion prior to my ownership ate through head gaskets that one eventually broke around same area that’s been machined with long studs so I don’t know which is better but the other interesting thing