For all those involved in the thread of responses about a month ago, I want to say thank you. I just want to clear up a point that seemed to have two different views. The secondaries must be fully closed to run correctly. Everything on my car is either new or rebuilt to factory specs. and I have tuned car in both ways mentioned and without a doubt the secondaries must be closed to get proper idle and throttle response. This is what I found with my car. Thanks agian .