I'm not sure about this one but my 07 Saleen came with 3.73 gears. Did only the S/C harleys or did they all come with them?
The Saleen supercahrger package includes only:
Series VI integrated screw type supercharger
Dual stage water -> air intercooler
39lb. injectors
Hi-flow inlet tube
"Powerflash" performance calibration
Performance air filter