Which master cylinder to use?

I have a 56 GMC that is sitting on an all stock 87 1/2 ton Chevy pickup frame. the booster and pedal ***embly is out of an 80's something chevy van. I need a master cylinder and was going to get a chrome one. Would use a 1" bore. I see some advertised on E-bay at a pretty good price but they say they are a universal fit to most boosters and can use a disc/drum OR disc/disc system. It has that corvette master look to it. I know a lot of the streetrod kits are based around a corvette master. I was under the impression that the corvette master was different than a disc/drum one and would not work. Is this true or does it not matter if I have the correct proportioning valve for the ch***is? Can a master be "universal" as they tote? thanks for any input on this..

 

You will want a 1-1/8" bore. Master cylinders have no idea what they are on, or where they are supposed to be. They are just chunks of metal and some rubber. It has to have the proper bore, bolt on to the booster, and properly engage the pushrod. That is about it.