No they are the same but depending on what spoiler you have there will be holes in different places when you take off the spoiler. If you are deleting the spoiler, or changing the spoiler type the cleanest solution is a new decklid so you aren't patching holes left over from the previous spoiler.
You have to read all teh posts above to capture the context. He was saying less downforce because the guy above him was wanting to remove the 2019 wing in favor of an ealier 2015-2018 track pack wing.
https://www.caranddriver.com/reviews/a27445671/2019-ford-mustang-shelby-gt350-by-the-numbers/
Interesting. So according to them the breakdown would be as such
If assume unscientifically the duck bill on my track spoiler makes 100lb more pounds that would put me at 286.... not far from the R. Probably more than a R style replica...
I wouldn't assume that much as the angle of a wicker bill has a big impact on the effectiveness of it. The ZL1Addons wicker bill that I have is basically at the same angle as the main surface of the wing. Really it just extends the surface area of the factory spoiler more than it acts as an actual true wickerbill. Also known as a gurney flap, due to it's creator Dan Gurney, it works best when it's perpendicular to the face of the wing/spoiler.
Nice marketing indeed, lol. I think the majority of Ford's reasoning behind this move was to save costs by having the standard spoiler be the same for both the 350 and 500 (same logic as sharing the block). Less we forget, the new "swing" was designed and tested specifically for the GT500 while the outgoing track pack wing was designed and tested specifically for the GT350.
Same reason the new GT350's share the radiator support bracket as well and some of the new front suspension pieces like control arms.