I have heard that later y blocks sonic test thinner then older blocks.  I have a 62 292 that I just removed the pistons that are marked .060 over.  I was thinking of having the block sonic tested to see if it would be worth using later?  My question is if the engine is now .060 over would it even be worth checking and saving the block?  What is an acceptable thickness of cylinder walls for a y block?   Appreciate help.