I bought the complete Y1 H & M harness for my `68 Barracuda, cost about $800. The only thing I did was plan-ahead and laid out all the sub-circuits I was planning on adding: electric fuel pump, third brake light, trunk lights, and electric trunk release out back and my MSD and electric fan up front, and made and installed it with the new factory harness. I'm adding in H-4 Halogens with relays this winter so I'll be adding to my additional harness I added. Everything opens up with the split-sleeve braiding so it's easy to upgrade and I also added an auxiliary fuse panel for my added circuits.