The story that I heard is that yeah....the bell housings were bored to the finished size when new. Rick Ehrenberg wrote about this in Mopar Action magazine. We've often swapped 4 speeds into cars with automatics and never checked runout and been just fine.
Why? Well, the guys at SST told me that the 833s were more forgiving of excessive runout than the newer transmissions like the Tremec TKO and TKX. Oddly, I'm just now learning of the spec the factory called for and it isn't much different than with these Tremec transmissions.