Can anyone tell me if there is a ventilated disc upgrade that I can do on my '76 3,osi?? I am redoing the brakes all around on this car and I cannot believe how big the front calipers are on this car!! I own 5 BMW's and these are bigger than any other one I have. A vetilated disc would be nice and I sure that someone out there has done this procedure. Another question......I am redoing the rusty exhaust on this car and I now find out that a rear muffler for this car is NLA anywhere. Does anyone know of an alterative muffler to use??? As usual, any and all help is appreciated.