Acutally there is a million wires under the brake booster.
To be a little more specific, there is a large connector called a "Self Output Connector", next to it is a smaller one with only 1 slot called the "Self Input Connector", and next to that is a female connector. These three thing, are each combined with black tape. The female connector is a single connection with a rubber protection, on this female connection is the Pink wire with blue strips. This is the tacho wire. Just get a male connection to go in it, or just simply cut it and solder a wire on to it. Then trace this new wire that you connected to the pink to the dash through the firewall.
1966 Blue Ford Galaxie - 4Dr Sedan, Pwr Steering, 302 Windsor, Edelbrock Performer Intake Manifold, 650 Holley Race Custom , Crow Cam 15666, Rollmaster Camgear, Heads Ported, MSD 6AL Ignition, MSD Billet Dizzy, Crane Energizer Roller Rockers, C4 - Stage 2 Shift Kit, HiStall 2500rpm, B&M Z-Gate Shifter, XY GT Radiator, 2.92 9" Diff, Dual Thermofans, 2.25" Dual Exhaust, RCI 16gal Fuel Cell.