OK lets think about this for a second. He has a 68 which already comes with a dual MC and a proportioning valve. He said the Granada has a "manual power booster", meaning that the Granada has manual brakes and a power booster. The power booster from a Granada will not physically fit into the recessed area of the 67-68 Mustang (I know I tried it). So if he can't use the power booster he does not need to replace the MC or the distribution valve.
You do not need to reroute the brake lines for a 67-68 granada conversion. The lines are the exact same size fittings and will connect with no problems.
So if the tie rod ends from the Granada are in good shape, technically he could reuse the Granada ends on the Mustang. So the only parts he needs is the one's to replace any worn parts. If he is not installing Disc Brakes:
He does not need a distribution block the 68 has one.
He does not need the dual MC the 68 has one.
He does not need an adaptive brake line, the Granada lines are a straight fit to the 68.
All he needs is some tools, cotter pins, and brake fluid.