Anyone running in IMCA Stock Car Class?

The reason I ask is the two local tracks, have decided to move the Pure Stock and Street Stock classes to the IMCA Stock Car class for the next season (one track will keep the pure stocks for and entry level class).  There are alot of questions we have floating around we're trying to get answers for.  
Like on the carb rule what modifications is IMCA talking about on the Holley 7448 to meet the specs of Holley 80787?  
Our main concern is, if this is going to slow our street stocks down.  For comparison our street stocks rules, your pretty much open on motor and tires, and can make a few changes with the suspension.  Now it seems to be that if your changing your intake to 350 cfm that will slow you down?
If anyone has any input this would be great.

Thanx.