Superchargers life....

superchargers used in OEM applications (both Roots and Twin-Screw) are designed to last the life of the car

do they? i've never personally seen a Lightning, SuperCoupe or Pontiac GTP with over 200,000 miles on them but i'm sure they're out there
 
Hundreds, upon hundreds of Thunderbird Supercoups have ecliped the 200K mark with their original Eatons still in tact. The Eatons may not be as cheap as the Centrifugals, or make the power of the big twin screws, but they're by far the most reliable blower on the market to date.