As I was doing my last minute double checks I found that injector #1 and #3 both had about 24 ohms of DC resistance.  After some investigation I determined that it was only #1 and #3 that had the problem on the common battery side wiring.  With #5 and #7 being OK there really was only one possibility.  One of the original Edelbrock connections had failed.  They connected these wires in a 'Y' matrix and there was only one of these 'Y's between 1,3 and 5,7.  I have heard from some other Pro-Flo user that they had wiring harness troubles.  Well they are correct, the original Edelbrock, or maybe it was Weber, harness workmanship left much to desired.  After lifting the air clean base I found this 'Y' connection.  After applying a little heat along with a lead/tin combination the problem was fixed.  I was extremely lucky that this failed at this time and was able to isolate it, and get to it.  Let me tell you that I wouldn't have been very happy if I had to spend a couple of days to remove the front of the harness again to gain complete access.  Now all I have to do is to worry when the others will fail!