We have a two-part Tech Tip that covers this thread and well as the
How to straighten your Rochester B or BC thread. They are in a nice, neat PDF format, very suitable for printing out.
The Tech Tips cover:
Part 1 - Common Issues covers a lot of ground (12 pages -
give it time to download 
) with a helpful schematic on the last page.
Part 2 - Casting Fixes (five pages) looks specifically at repairing warped Air Horn and Fuel Bowl castings, with helpful details and images.
Both parts can be found
HERE in the Engines Tech Tip forum. There is also a follow-up thread
HERE for Q&As, comments and the like.We are locking down this thread so the discussions can be held in the Engine Shop.