more then likely .. brushless classes are ran as that ..Brushless .. stock 13.5 BL .. 4300 BL (supposed to be equal to 19t .. then Mod what ever you fancy .. Some clubs allow BL to run with Brushed depending on entries for that class ... Really depends on the Clubs , and the amount of enteries for BL and Brushed .... might want to get intouch with your track or tracks and ask them as everyone has there own rules ...