14. The new Detroit Speed rear multi-leaf springs have a rate of 175 lb/in and incorporate a 3-inch drop. According to Detroit Speed, what sets their leaf springs apart from the others is that these provide excellent handling without sacrificing ride quality. Their tapered leaf design and anti-friction pads really help smooth out the ride. They came with rubber bushings installed, but we had Detroit Speed’s poly bushing kit, so the rubber pieces needed to be persuaded out with a hammer and large socket.