Hopefully you can find a .245" reamer on ebay.
I looked through the videos for one that was specific to Callies block prep, it was a little scattered throughout the build but the lifters are the worst thing and they are in episode 5, Here's a link:
https://youtu.be/2YW0rVTbXhA

There is other Callies info in the whole build. Here is a link from the beginning:
https://youtu.be/iKkjpiraZnw