There are the dual system master cylinder kits that fit on a special welded bracket that bolts directly to the same bolt holes in the frame as the original factory unit does. They also have a kit that you can do the same thing, and is a boosted dual master cylinder (power brakes).
That is why I ask. I'm not talking at all about Disk brakes, all that changes is separately connecting the front brake system to one chamber and rears to the other. It looks simple and easy, I will be helping a friend do this to their truck soon. And will do it to mine if and when I get it.
Not big bolt, though. I'm thinking there maybe a bit more capacity to the master cylinder for the big bolts?