Rear coil springs...Moog #5379 variable rate approx. 3 yrs. old. still in great shape...$35. shipped o.b.o....Factory posi. unit...108,000 miles. Still works great but could stand a rebuild if planning alot of hard racetrack launches. It is out of an 11.00 car and occasionally the left tire would not spin as much during burnout. But it is fact. and rebuildable....$65. shipped o.b.o..Thanks.