Not trying to piss on your idea, but there are lots of parts that are different besides the fairing and headlight nacelle.
Gauges, radio (obviously), wiring harness, tank bezel, ign switch, gas tank, windshield, just to name a few.

You'll be better off (with both time and money) if you just add an aftermarket bat wing fairing that holds speakers and a radio and not messing with all of the other stuff.

 

Yeah that's why is didn't put "Can I make my Road King a Street Glide". That's not what I want. I want:
1) the profile or look of the Street Glide. I have an aftermarket fairing now and it does not sit like or really look like OEM but more like what it is an aftermarket fair imitation.
2) I would like the speedo and maybe 1or 2 of the gauges to be on the fairing. My speedo is light gold in color and in daylight it is hard to see and forget about the warning lights, you cannot see them. I currently have something called an Aoocci C6Pro that give me readouts for tire air pressure and temperature, speed, GPS location, maps and even has front and rear cameras with recording. Oh I also have Android auto which means I can pump tunes or Google assistant into my helmet.

In short I could even put my current C6 Pro into the dash of a OEM fairing and be happy as long as it doesn't look ghetto with open holes where gauges should go...

 

There used to be company called Dragonfly Concepts that made full fairings specifically for the Road King. I'm having trouble finding their website now unfortunately. But maybe you can try to snag one of those.

DETACHABLE BATWING ALL FLHR

One Set Stainless Steel BracketsOne 12-Volt Accessory PortTwo Speaker GrillsOne Set Mounting Hardware

ftcycle.com

 

There used to be company called Dragonfly Concepts that made full fairings specifically for the Road King. I'm having trouble finding their website now unfortunately. But maybe you can try to snag one of those.

DETACHABLE BATWING ALL FLHR

One Set Stainless Steel BracketsOne 12-Volt Accessory PortTwo Speaker GrillsOne Set Mounting Hardware

ftcycle.com

I researched Dragonfly, found they went out of business. Looking at their fairing I can tell you why, cheap Chinese knockoffs flooding the market at 1/3 to 1/4 the price. In any event, they do look much more like OEM at least from the front. But from the back they look like and really are nothing more than a stereo. My personal preference is to have my tunes in my helmet. What I want is more of a dashboard with instruments (not necessarily OEM's) helping me to monitor the condition of my bike and my ride.

 

It can be done pretty easily. You are much better off if you have a donor motorcycle there are so many parts you’re gonna need such as hardware, wiring, brackets, etc. It’s just a lot easier if you’ve got another bike there strip off of. If you plan to collect the parts, get a manual and make a list. It’s gonna take a while.

You’ll have to decide how far you want to take it. Are you going to swap the tank, etc.?

There was no 2005 street glide so you really didn’t have anything to copy. Do whatever you want.

 

I recall seeing what appeared to be a combined setup like this many years ago, but instead of adding the batwing gauges, they added speakers to all of the holes of the factory-style inner fairing, which essentially left the RK tank and gauges alone.
I can certainly understand why they chose that approach over messing with a full convert...

 

Yes! I remember seeing that set up as well.

 

I went the aftermarket route on my Road King so I'm no help.

 

Actually you can be. Do you find your aftermarket fairing sits and is positioned like OEM? I have an aftermarket one but it is the cheaper outer version (see pic) and I have added a pouch at the top for storage and the screen is my "dash".

 

OR you can purchase a crash bike at auction that has all the correct needed parts to convert your bike ! ? Plus you'll have a garage full of spare parts to do a project bike in you spare time ... if you have any time left ?