Cylinder wall weld??

That looks odd and shoddy to me.
I have never seen a repair like this before from the factory.
Did it run okay and seal before you took it apart?
Or, have you never run it?
I would be looking for another block to build if it were me, after all, it's only a 318 and there are a lot of cores around for cheap.
That's my take on it FWIW...