Alright I'm going to swap my front brakes out for the gt style brakes so I can run a 15inch rims and put a radial on it, now with keeping the back the stock Gxp brake setup will I see problems? Will keeping the stock 18 on the back help on the track?

i know why not just put a 18inch drag radial on the front but I wanna get a set of prostars and be light vs our 18s and it'll loo tougher. Might do the back to so I can run skinnies