What is this and why would it be there?

My guess is this'll be the boogie monster under the goop! 70 1/2 340 block.View attachment 1715417144 View attachment 1715417145
Max, I think you hit the nail on the head, because the side wth the goop on my motor has very little machined relief that is been one of the suspects in this dicussion. So here's a question for you - was that motor weeping coolant, and if it was, what did you do about it?
Does anyone know what the goop in my motor is? It's not any type oh epoxy I've seen before.