This is a factory correct distribution block for 1965-66 full size models when converting to dual master cylinder or disc brakes.This block mounts to the frame and has two provisions for dual master cylinder lines that screw into the top whi le the left and right front screws into the sides and the front to rear screws into the back.Often these blocks are missing or discarded with the old lines. This brass block is an exact reproductions with the correct size shape and thickness. {specs}.