Late flathead heads on 59 block

[bchrismer]

I recently was gifted this set of heads from the estate of one of my dad's best friends. I had known OF them, but had never seen them, but had asked him to sell them to me for as long as I have known about them.

I know you can run late heads on a 38-48 block with modifying the head to block a water port. Is that what I am seeing in the second photo?

Thanks.