Cold weld is the best IMO..... "drill & tap holes along the crack & thread in plugs overlapping"
There's a valid point to doing it that way.
Primarily because once welding occurs on cast iron, the molecules will try to move away and re arrange.
Others claim it stretches the metal using inserts thst overlap.
The size and depth of the crack and location are factors as well.
I was fortunate to have my original head repaired from a Jedi iron master welding it.
Probably he is the best in the west.
After talking with him; he re assured me his repairs are top nothch.