[Tony Corley]

I don't think they are limiting boost, just the way that you make it. Changing pullies should be illegal, same as running a cam over the specified lift is. But just like a cam rule, it's what you can do in between all the variables makes the difference. Any blower is going to have a limit of what it can produce, and specifying pulley size helps limit it. For the record. I have not raced Stock. but have a lot of experience with a power adder class that used to exist with a another sanctioning body that had very strict rules, similar to stock. Pully size was specified, so then it becomes a matter of reducing restriction, (porting was not allowed), and increasing rpm's.No different really than a naturally aspirated engine.