I could be mistaken, but the 465 and the 475 "kits" were the same except for the tune (that may be a debate as well).
The only two differences I can recall between the 2008-09 Racecraft and 2008-09 S281 S/C are...
1: Bottom of the stock airbox was not cutout on the Racecraft.
2: The Racecraft ran OE Ford Motor Company mufflers.
Someone that owns one of these vehicles may have more details.
The "old" Saleen S/C upgrade kits were marketed towards owners of 2005 & 2006 S281 S/C editions and people that purchased the Series VI in the aftermarket during 2005 & 2006.
The 2007-09 S281 Supercharged cars have the physical content (intake, pulley, injectors) from Saleen... though the tunes may be different (may).
I could be mistaken.