I have a Mancini (made by Strange) aluminum master cylinder. The instructions that came with it say it is for 4 wheel disc brakes only. I will be using rear drums, so ended up purchasing an aluminum master for a 1980 Volare with manual disc/drum brakes. I checked the plastic reservoir and the large side of the reservoir is in the rear, which would be for the front brakes. I never checked the Mancini master to see if both sides of the reservoir were the same size.