I have a 2000 Silverado and I'm wondering if I could upgrade to some of the 2004 Silverado tail lights on my truck without major modification. Has anyone done this? Is it hard to do?

 

yes it's extremely easy. The only thing is that right now you have a 3 bulb harness and the 03+ have a 4 bulb harness. It won't affect anything but some people like having the extra bulb to make it a "complete swap." Personally, I'm lazy and I did the swap over 3 years ago and never converted to a 4 bulb harness.

Here's what you need to do
1.) Buy taillights, I would also recomend buying the harnesses which are a direct plug and play
2.) If you decide not to buy the harnesses you will need to modify the light sockets a tiny bit. A dremel works great. It takes about 3 minutes to do both sides and won't affect the lights one bit
3.) There is also a way to modify the stock harness and add the 4th bulb, but I won't get into that.

There is a how to around on gmfullsize somewhere if you really need it, but honestly it's a walk in the park. I did it when I was 17 years old and barely knew how to turn a wrench.

 

03+ Tail Wiring Harness' P/Ns
16531401
16531402

 

I have a gmc, which has the 3 bulbs, the new silvys has 4 like said, I too only am using the 3 bulbs, kept the stock gmc harness, had to mod the bulb fastners a lil, but very easy. I just covered the 4th light hole on the side of the silvy lights up.. Look great..

John