I have honed bb mopar cam housing bores before using a hone similar to the one pictured.

The biggest challenge in taking out as much as .006 will be preventing taper or bellmouthing the bore.

It won't take very much honing to do it. Exactly how long will depend on how much tension you put on the stones, rpm, and lube used.

Hone a little.... Check size and taper.... Hone some more, etc.

My understanding of how the factory did it was that there was a 5-step reamer used on the bearings themselves that did all 5 at one time, in place.
So it didn't matter if the factory cam tunnel bores were all that round or perfectly in line with each other....... Being sized in place, all at the same time made it less critical for that part of the block to be really "right".

I've actually gotten sort of burned by a screwed up cam tunnel on these motors before.
You have the block all done, then you go to install the cam bearings only to discover there is some issue with the cam tunnel.
Now, after the block comes out of the cleaner, it's the first thing I check.