One more time I will repeat my experience with cracked block repairs. I grew up in a Chevy Dealership owned by my Dad. This was back in the day when things were repaired rather than replaced primarily because money was not available for that. This dealership also housed a full machine shop complete with forge, trip hammers, gas and electric welders, a big a$$ drill press, three station grinder, lathe, and everything a repair facility would need to keep farmers and loggers going after they broke stuff. I should also remind you that labor rates were not $90+ per hour either. Tractor blocks tended to crack because once the harvest was done the rigs were parked and antifreeze was typically not checked. So -- depending on where the crack was, if the surface was relatively smooth and did not have compound curves, that area was ground smooth and a small hole drilled at each end of the crack to prevent it's spread. A steel plate about an inch or so bigger than the crack was fashioned and then a series of drilled and tapped holes were closely spaced around the plate. A gasket was made and it and the plate were then bolted to the block. I never saw one of those repairs leak. If one is reasonably handy and has the tools, this is a job a DIYer can do. The down side is the crack needs to be outside only, must be on a relatively open area of the block with no bosses or other protrusions, and the engine would likely need to be pulled for the repair. Modern engines do not generally have large open areas on the block surface so one would have to be very lucky to pull of this fix. However, I saw it work on many occasions back in the day. Unrelated to this, it was not uncommon for someone to knock on our door on a Sunday morning wondering if they could get a part welded while they were in church. In those days, a valve job could be done on a 6-cylinder Chevy in just a couple hours and again, I saw it happen on a Sunday morning. You kept customers happy in those days.