Be sure to take a really good look at the 8mm bolt that helps hold the super charger pulley in place for any signs of being removed.
If there is any evidence of a wrench or socket having been on it, like light scuff marks and such, i would pass.
The 03"s also had some problems with the heads and if they were over boosted there would eventually be a knock of some sort like a bad lifter or bottom end issue. Be careful.