On attaching the bracket to the dash I’ve noticed that the face of the bracket in contact to the dashboard is not flat. With the lower two 3/16 nuts and setscrews tightened the top 1/3 of the bracket is not in contact with the dash and even appears to be slightly concave. Should there be a spacer/washer between the dash and bracket where the 5/16 setscrew attaches? Without this the dash could be twisted when it is all tightened up.
Milton
Assuming the back of the dash is flat, preferably machine the bracket flat or use a washer or two as a spacer.