Recording Fallout 1 with shadowplay

So the original fallout is fixed in a 4:3 aspect ratio which is fine for playing but i want to record it for a you-tube series and wanted to know what the best solution is.

Normally i use shadowplay since its pretty efficient and my hard-drive space isn't unlimited. I want to know if when i record shadowplay will keep my full monitor resolution and 16:9 aspect ratio so i can then add a nice border on the bars on either side in editing?

If this will not work can someone recommend another program that i can use instead? thank you also sorry if this is the wrong category i really didn't know where to put this.
 
Solution
I haven't checked Shadowplay options in a while, but if I remember correctly all you have is quality settings and resolution settings. I have a 1440p monitor but Shadowplay record in 1080p for uploading to Youtube. FRAPS has more options to record (the pay version) but it is extremely heavy on file size. Here's a thread from four years ago that may help:

https://encodingtalk.com/threads/fraps-changed-aspect-ratio-from-16-9-to-4-3.2709/

Another option is to buy a video editing program where you can create any aspect ratio or resolution you want (I have Sony Vegas Studio and love it).
I haven't checked Shadowplay options in a while, but if I remember correctly all you have is quality settings and resolution settings. I have a 1440p monitor but Shadowplay record in 1080p for uploading to Youtube. FRAPS has more options to record (the pay version) but it is extremely heavy on file size. Here's a thread from four years ago that may help:

https://encodingtalk.com/threads/fraps-changed-aspect-ratio-from-16-9-to-4-3.2709/

Another option is to buy a video editing program where you can create any aspect ratio or resolution you want (I have Sony Vegas Studio and love it).
 
Solution
Far as my experience goes the resolution setting in shadowplay is more of a suggestion,it will automatically record in lower resolution if what you play is in lower res.
What you can do is play in windowed mode and have your desktop at whatever res you like(1080) and then record the whole desktop that way in editing you can substitute the desktop with anything you like,like the borders you mentioned.

Also if you have the windows version and not the dos version there is a resolution patch to play it in higer resolutions.
https://www.google.gr/search?q=Fallout+1&oq=Fallout+1&aqs=chrome..69i57j69i60l2&sourceid=chrome&ie=UTF-8#q=Fallout+1+resolution+patch