A suspension assembly for a vehicle having a first suspension coupled to a frame of the vehicle by a plurality of mounting brackets. The suspension assembly includes an adaptor having a plurality of mounting portions configured to align with and be coupled to the plurality of mounting brackets of the frame. A method for modifying a suspension of a vehicle includes uncoupling a first suspension from mounting brackets secured to a frame of the vehicle, coupling adaptors to the mounting brackets, and coupling a second suspension to the adaptors.