I made 2 six inch brackets w/1" L bends to mount a Slip-Streamer Spitfire tinted wind shield (4" wider & 3" taller than the OEM shield). My goal was to allow 1.5" - 2" air gap at the bottom to achieve an angle similar to the forks . . . Which should reduce buffeting etc. I wanted to keep it chin high to allow full view over the top etc.
I used neoprene/rubber gaskets between my bracket spacers . . . using the upper fairing mount hole . . . which will help hold the shield in place. I used neoprene gaskets on the shield mounts too. I had to drill new holes 3" from the bottom of the Spitfire shield.
For my 5' 11" height I moved the shield 2 3/4" above the stock shield (using a split rubber hose as an edge on the stock screen) to protect the new shield. The bottom of the shield is above the light with a 2" air gap to counter buffeting.
It works great at any speed. It can be adjusted up or down as needed.