I'm doing a full 4 corner brake upgrade to X-drilled rotors, street pads, brake duct kit, and braided brake lines. My braided brake line kit came with 6 lines, I know the 2 smaller ones are for the rear and the 2 larger for up front of course, but the kit comes with an extra small and extra large, where do these lines go? Or are they just extra in case one leaks? Also for the duct kit has anyone had a problem with stones or dirt getting trapped in between the break rotors and pads and scored them from using the duct kit to the hose adapted backing plate? I was thinking of putting a mesh screen or something where the duct inlet meets the hose, that way nothing to big could pass through and do damage.