The disk conversion kits are not expensive, but you also have to buy calipers, rotors and hoses.
And you really need to convert to dual master and replumb the brake lines at the same time.
I did it on my '55 1st Suburban about six years ago, so my memory may not be complete, but it wasn't a huge job, just took some time and money. I had already installed a '73 Chevelle rear axle with five lugs under the rear.
