stillen pulleys

bucketman

The standard or stock size pulley is a light weight pulley. All the accesories will spin at the factory speeds but because of the weight factor the engine will rev a little faster. The under drive pulley is light weight also but because it is smaller all the accesories will spin slower(alt. a/c etc.), this will result in a faster rev up and a little more horsepower. Not super difficult to install, but care must be taken to get the new pulley lined up true. If you haven't done one before, I would suggest having someone who has, help, or paying someone to do it.