[Keystone 34 3w]

I see no problem with welding the damage. With today's advanced techniques on a block with low impurities , a welder should be proud to do this job. Once the area cleaned and dry with no moisture, bake the block in an oven in an area with no drafts , weld and cool down as slow as possible. Machine surface the repair. You may have to sleeve that bore depending on how deep the crack goes. I can't see that in the picture. I welded a 36 , years back with stick rods on reverse polarity and all went well other than I had some moisture in the block and that cause some grief. Your block looks dry , and remember this metal is purer than blocks cast in the 60's and up. I recommend you strip the block bare and clean
it to look more tempting for a shop to take it in. Hope this helps.