Sorry to say guys the 6 piston Brembo upgrade on a non 1LE 1SS or 2SS is not (currently) legal for SCCA Street classes. Here is the SCCA definition of a "Standard Part".
standard part An item of standard or optional equipment that could have been ordered with the car, installed on the factory production line, and delivered through a dealer in the United States. Port-installed options provided by the manufacturer are considered to be the same as those installed on the factory production line. Dealer-installed options or deletions (except as required by factory directives), no matter how common or what their origin, are not included in this definition. This definition does not allow the updating or backdating of parts. Manufacturer options which are dealer installed must be specifically listed in Appendix A in order to be eligible
However there has been a proposal in the SCCA January Fastrack newsletter to change this to include dealer installed options and the 2016-2017 Camaro is specifically referenced for the brake cooling parts that come with the car. They also mentioned some of the other additional items you can order with a Camaro through the ordering process that are installed by the dealer upon delivery.
https://dk1xgl0d43mu1.cloudfront.net...pdf?1483478855 (bottom of page 27 and page 28)
My feeling is that this will eventually be changed to include these items, but that they may also come with a bump to a different class if their performance advantage is significant enough. I don't think that an upgrade from a 4 piston brake to a 6 piston brake would necessitate a bump to a different class but it's possible.
Bottom line is that
RIGHT NOW the 6 piston Brembo package is
NOT LEGAL for SCCA F-Street. If you did order this from the factory on a non 1LE 1SS or 2SS and it is on the car now you will be bumped to either STP, or CAM class. However keep in mind that local chapters may be less than strict about this, but if you expect to go to any of the SCCA Championship Tours, Pro Solo's, or Nationals they will not be allowed, you
will be protested. The likelihood of this becoming an issue at the local level will vary and will be directly proportional to your propensity to win against the other drivers in your base street class.
TLDR: 6 Piston Brembo's are not currently legal on any 1SS or 2SS 6th gen in F-Street. There are proposed rule changes to possibly allow them in the future, but not yet. For local competition no one may care unless you are beating them too often.