That crack can also be welded. Any good welder that is worth his salt will use low temp rods and do a good job. You can solder it for a temporary fix. Just drill the ends of the cracks so it doesn't keep on cracking. Sometimes it is more important to keep the orignal engine than put something new in. I have had blocks welded where they have put them in a brick kiln and heated them up to around eleven hundred degrees(bright red) and hot welded them. But then we didn't throw things away like they do now, we fixed it.
Oly in Oregon
Rest in Peace1945 GMC COE Victory Truck
1953 Willys CJ3B
1955 Chevy 1st series 3/4-ton
1958 WIFE Last series
Never say "Whoa" in a mud hole