Here's NewEgg's response to my question, if the Q6600's are g0 stepping.
...Generally, our stock moves so fast that we have the latest version or revision of everything. Unfortunately, we do not
have a way to physically get our hands on an item and tell you what revision we currently have. We do not guarantee revision numbers unless it is specifically noted on the description on the website...
Based on that, I will probably end up purchasing my q6600 from ClubIt since they guarantee g0 step'n.
How long ago did b3 chips stop being produced?