http://raptorforumz.com/showthread.php?t=1044
read that thread. I just put a system in my Raptor and it was a lot more than we expected. There may or may not be a factory amp in ur truck. take out the center console and you'll find out.
if you need a hand with anything else, let me know. I also posted some pics and explained a little in this forum. hope it helps