My Blazer is stock, with all the emissions stuff still there. I have found out it prefers 12btdc. You will notice a performance increase if bumped up a little as long as it's not pinging. I am connected to full manifold as per the hose routing diagram, QJet is not electronically controlled. I'd try timing, be sure there are no vacuum leaks and check the cats for flow. Maybe you can come up with something if you try a search.