Just looking at the two different models I would say yes. I think they will bolt up to the heads ok. If there is a problem it may be at the rear attachment point, where they bolt to the frame. Maybe someone else can give you a definitive yes or no. Good luck.
my bad about the 2009 miscue instead of the *2006* Spirit and also had the incorrect Shadow too becuz the suffixes (vt xxxx) can be cryptic. Try here, may take a few seconds to load. You're looking at part 20. Is that the bracket on your Spirit? Note the two bolts mount horizontally to the frame. The remaining two bolts/two studs should fit (interface) different mufflers though (I think).
If you've heard that Spirit exhaust ports differ in design from the Aero/Ace exhaust ports, that's a concern definitely. Perhaps inquire at the Ace Forum, post a reverse question if you prefer.