Block crack - is this terminal

[Austin in the Shed]

I guess it's how much you want to save that block. As others have said laser weld, Weld with one of the alloying/nickel type  rods,stitching or possibly drill and tap  and plug several places along the crack and seal with irontite which works well.
Check if the block has any other serious problems,It looks pretty rusty.Will it bore bigger ? how many broken studs etc.
I had one crack in the same place worse than that whilst out of the car ,dry ,in storage ?