first, exactly what mustang brand and model number did you buy?
As tj said, make sure the mc air bleed hole is open
looks like you put chrome acorn nuts on the bottom adjusters which is not correct.
The way to adjust is shown in the attached ford bulletin.
The bottom studs have flats on them with a punch marks as shown below
i have that bulletin of yours enlarged and hi-lighted.
Way ahead of you on the acorn bottom adjusters. Those larger stainless, chrome (depending on size) acorn nuts are from iowa 80 in walcott. They are press on covers. So the bottom adjusters do work. However i have not adjusted them as per suggestions from above.
I do not know which mc i did buy, or even where i bought it from. My receipts only go back 3+ years. It was either advanced or napa. I do remember having to return one mc because it would not match the adapter mounting holes. Even the 2nd mc (the one i had powder coated) i had to elongate the mounting holes around a 1/8" on each side.
If i had grandson take a picture of the mc, could you tell what it is by the pictures? Thanks
