When the Head is removed besides have it checked to see if it is still Flat they should do a pressure test to see if it leaks anywhere.

There is a few ways to fix external leaks but if you need to pay someone to do that it is not worth the trouble. Also someone doing that type of repair needs to be more skilled than the average Mechanic.

Also, when an Engine overheats it is more common for the Head to warp and maybe crack or for the Head gasket to go.
Once in a while Blocks crack but if it is due to overheating the often Pistons Skirts will also be all chewed up and the Cylinder walls will not look so good.

It is more common for a Block to leak due to some casting flaw or porosity.

The Block can also be Pressure tested if they have a Plate or Plates made for that.

.

__________________
84 300D, 82 Volvo 244Gl Diesel