My 87' likes the 3-wire. I used a Bosch 20A relay mounted next to the wiper motor, ran power/fuse to the firewall stud and grounded directly to the ground strap coming off the driver's side head, at the wall. It really makes a difference coming down to idle when it's cold, like nobody said. Running the relay off the Orange ignition circuit works great. If/when you go headers, you can run the O2 pointed straight down into the bung and relocate the bung further away from the exhaust manifld. Because it is heated, it will warm up on it's own and last longer than a year, like the one wire is rated for, by moving a foot down stream. Just rout your wires carefully. The exhaust will eat your wires, if you do not plan on tying them down well.
My only option was a double zip, loosely around the shifter linkage. It has worked well for over a year.