i heard if u get the 03 taillights then u need a something to make em fit?

 

the only thing you will need is the harness if you ant to use all the bulbs.if you dont have the haraness the will still work you just wont get the last little bulb to work.

 

They are easy. They slide on just like the old tails do. But for the little extra light, I did not buy the original harness. I just went and found some license plate light harnesses from a NBS GM truck. They are the same plug as what would fit in the extra light hole anyway. I wired them up and they worked flawlessly. Just like they would on an 03.