The easiest way to convert an earlier LINC (in my opinion) is to find a later LINC 65/69 that uses KELSEY-HAYES four piston caliper brakes. Take the spindles, brake parts, rotors and the proper dual master cylinder/valving for the system. This system caliper is a non-sliding four piston design that has a tendency for piston freeze-up. The typical solution is stainless sleeves/pistons.
It is also possible to use the spindle from a mid-seventies intermediate to convert to single piston sliding caliper brakes. This will require some modification(s) in brake tube routing and valving.
http://www.hotrodders.com/t34753.html
I have also seen advertised on e-bay a GM changeover kit that bolts onto your existing spindle.
