I know for a FACT that a car won its class Stock last year, with an E-brock intake on it.
I got put in the F-4 class last year. the tech line guy told me do to my intake , headers, and window louvers.
I think the louvers are fine now. the rules say any parts that were available for your car that would of been used on your car can be used. last year if you had louvers , you had to so proof it was a dealer install on your car.