I guess the mustang rear could be worth it probably if it was out of a GT, even with cutting all the brackets off it. Those come standard with limited slip and disc brakes and often with a popular ratio. Not sure if those are the right width without shortening them. Also wondering if the GT has the heavier duty splines. Not opposed to cutting and welding the tube. If i go that route i will be making the weld seam where the spring perch on that side will straddle the weld on either side of it to reinforce it a bit. Just asking the questions since I am now shopping for one of these for my kids car as it makes more economical sense.