It still should be tuned for the radio, connections, wire loss and location on your vehicle. firestik has a good write up on the terms "factory tuned" and "tuneable tip" and what they really mean. http://www.firestik.com/Tech_Docs/TUNABLE.htm
heres a little excerpt :
This DOES NOT mean that you can screw the antenna into the mount and go. CB antennas are not plug-and-play devices. "Factory Pre-Tuned" only tells you that the manufacturer has established a standard frequency for the production of their antenna(s) and that the antenna was manufactured to meet that standard. The manufacturers standard refers to a given frequency … NOT a specific SWR reading. Furthermore, the standard is developed on a specific and fixed ground plane. It is doubtful that your vehicle ground plane would match that of the test standard ground plane. You MUST set the SWR of all CB antennas after the antenna is mounted in its final location. Failure to do so will limit the performance of your system and could damage the radio’s circuitry.
also here is a review of the antenna you have and he does get it tuned http://www.cbradiomagazine.com/Jan%2...a%20Review.htm
im no expert this but i did just go through a CB install and learned a thing or two.