This has been addressed a number of times so definitely worth a search on the board, but yes the consensus is to use the 15/16 bore master cylinder, as shown in the link (or if you are not worried about looking stock-ish, an aluminum 15/16 based on the later model if anyone is still offering them). Note the original application for the iron one was mid-70's A-Bodies with POWER brakes, don't be put off by that, this is what you need for your manual discs on your Cuda. The 7/8" rear cylinders also a good idea, though you have 11" rear drums rather than 10", so not sure if this would affect that choice.....