The Stovebolt Site Forums The Shop Area General Truck Talk Master Cylinder

You can find a narrow bore NON-BOOSTED dual master to bolt into the stock location using the stock pedal and it shouldn't cost too much at a FLAPS. Something from a similar size/weight vehicle with the same type of brakes (four wheel drum).

You can make your own bracket to mount it or buy one from any number of suppliers. Making it isn't too hard. If you don't have either the drill or welder you can mock it up out of cardboard and have a machineshop make it for less than the $90 the bracket costs new.

If you use the dual master you might also consider the proportioning and residual valves.

There are lots of threads on the conversion. Try the search button.