Intercooler problems were on the 99-00 years and not 01's. I'd check and see if the truck has been modded. Look to see if the lower pulley has ever been removed. If so it is likely it had a larger pulley on it at one time. Check the computer to see if it has had a chip - if the coating on the terminals is gone it had a chip at one point.

If this one is sold at a dealer get the VIN # and check and see if you can get a hold of the previous owner and get an idea about the vehicle from them.