I am eventualy going to buy the 5 lug disc brake kit from either classics or brothers (probably the same one) for my 51 GMC my question is i know they offer the master cylinder for a disc/disc conversion. im sure that the master cylinder they offer has to be offered by a local parts store for a lot less $$$$ it has to be a particular master cylinder for a certain year chevy truck. does anyone know which one it is. I want the master cylinder to attach to the chassis like the original