You have to add an additional wire to go from an 80e harness to a 60e harness. It can be done but its not as easy as converting from 60e to 80e since all you have to do is unplug one wire and move another from its original location to the place you unplugged the other. I did that conversion on Bud8Fan's harness this weekend, took about 20 minutes under the hood at the PCM to move the wires around.