Dennis, I did some research on the extra wire a while ago. What we came up with, was there is a jumper wire that goes to the idle control solenoid from that connector. Other forum members and I could never prove that the 1970 454 ever used that solenoid. Willie lent me a bracket that we thought would work for our cars. Dan Janes (overdrive) fabricated a bracket and I found a solenoid on line but it really didn't help. I have it and the harness if you need them. I hope that helps