My truck is AWAL not just rear wheel. It will all go.To retrofit the TBI stuff to a Vortec truck, you'll be deleting the rear wheel ABS which you didn't even pull I don't think. To thread that single rear line directly into the proportioning valve you're going to need an adapter. For the life of me, the size escapes me.
First image is similar to what my truck has. Second is the set-up I pulled from the donor minus the RWAL required parts. My plan is an adjustable prop valve so I can dial in rear bias as needed (taller rear tires vs fronts).