Holley Idle Screws Not Responsive

Sorry George but I keep forgetting to take a picture of the engine compartment.

After all of this tinkering, I still had one idle screw that was not responding at all. I also had a terrible stumble off idle. After trying many things (like larger squirter, different accelerator pump cam and many cleanings) with no improvement I switched primary and secondary metering blocks. No more stumble and the same idle screw is not responding on the secondary side. I would have to say that there is a defect in my primary metering block and I'm going to order a replacement.