My 69s had the 4 piston calipers.My 70s had singles.I know for sure my one 70 had a GM rotor on the front.It was there when I got the car and was still on 3 years later when I sold it.One of the hardest things to find especially on 70s is unbroken front turn lens.Seems they got broke a lot.I saved a set for my 70 and a set for my 69.Still wish I had the cars.Rocky