you really should do a retrofit or use TYC's, BUT you dont exactally need to. i have my HID kit in my stock headlight. alot of people will say the only way to do it is with a projector blah blah blah, but honestly, you can do it right with reflector housings....just make sure you re-aim your headlights and point them a little bit down so you dont blind the sh!t out of people. thats what i did, havent gotten highbeamed once. as far as output, yea, i notice a difference, certainly nothing as good as a projector would do, but def better then stock halogens.