Hey CBASS, relax, im sorry what I said earlier bothered you. I simply remember reading a dozen previous posts comparing the MM's to the Pro3i's, and in all cases, the conclusion was that they were identical with the exception of the bushings on the chassis side. The MM's do use a 3 piece design, and I am almost 100% sure that the Pro3i's dont. If they did, it would definately be advertised here:
http://www.partshopper.com/fordmustang/Itemdesc.asp?CartId={A2F17208-51E0-4077-8EVEREST10A-6DF538DB92AC}&ic=PRO3%2D23957&eq=&Tp=
Ofcourse, there is no mention of a 3 piece design. Im not saying you can't have better 60 ft times or good traction with the Pro3i's, im sure they made a huge improvement over stock. The fact that your 60's have lowered does not say much about the QUALITY of the arms. I had a crappy pair of X2C control arms in my car with solid bushings at both ends. Hell, my car felt fine and I was definately getting more traction. The only problem was, 10k miles later, the bushings were completely shot. Its not the end of the world not having a 3 piece bushing design at the chassis side, but it is damn hard to avoid bind without them. Anyways, im not knocking the pro3i's, im just giving my own opinion here.