Wilwood 250 14046 Wilwood Caliper Mounting Kit w Bracket GN6R 3.50in Mount Pin by Brian Oliver on Tattoo inspiration Astronaut tattoo. Wilwood 250 14046 Wilwood Caliper Mounting Kit w Bracket GN6R 3. 50in Mount Wilwood's 3. 5" bolt center GN6R bracket kits allows spindles originally configured for use with 3. 5" bolt center lug mount Superlite series calipers to accept the GN6R radial mount calipers with the original diameter rotors. Bracket kits include studs, shims and the mounting hardware. NOTE: If larger diameter rotors will be used with the GN6R radial mount upgrade, the lug mount attachment points on the spindle will require relocation to the appropriate height for the new rotor diameter. Contact the spindle manufacturer or the chassis builder for specific information on updating your spindles.