You can get it fixed that will last the rest of the life time of the engine. You just have to find the right shop to get it done in. That is what is called a foundry crack. In today's world there are not many of the old guys that can do this type of work. But check in a diesel mechanical shop where they work on semis they might know of someone who still does this type of repairs. Or check with a restorer of old cars, pre1960's, they might should know too. For some of their work would be on engines that can not be found any more that need the casting work done to then.
That is on of the old arts that has been almost lost now days. But there are a few out there that can fix it just takes sometime to find them.
A 89 yj with a 4.0 aw4 sye out of an 92xj. Now the hard part is done time to get it up in the air just a bit. Working on 8.8 with 3.73 and lsd for the rear. and new D30 hp with 3.73 .
For those who have not figured this out I'm old school but can handle the new too.
im just cheap, and cheap makes you creative.