Two pistons did clean up from carbon pretty easily, I figured these were the ones where I had leaks before. That said, thats where I had an issue, but the level and balance of smoke now compared to before is drastically different.
I did not see any cracking or evidence of such on the block or head.
I would have thought it more likely to damage the aluminum head than to crack iron the block.
If I remove the heads again I will look more carefully for cracks. I reviewed the pictures I took but nothing is apparent there. Might not be able to find a crack without magna fluxing the block.