Oh yesssss
I bought the kit with the inserts, the drill and the special tap.

The inserts have special threads that are angled up and they "pull" pull the crack together.

The idea is to stop the crack from spreading and to maintain proper torque on the bolt.

IS IT PERFECT.....NO.....But this fix has a good track record.

I have done a couple 6.5 bottom ends..

Welding cast iron is a tough slog even when the casting can be spotlessly clean and contaminate free....

Oil soaked casting is just a loosing battle......

I assume the crack is in the outer bolt hole ???

As you probably know...GM reduced the bolt diameter in the 6.5 outer bolts to 10mm from the original 12mm

This does leave a bit more material in the area....but cracks still happen.