I want to put a set of Buckhorns on my 2005 XLC, and run the wires inside the bars. Anyone have experience with this. Will I need wire extenders, different throttle cables, etc?

 

If you have the flat drag style bar you will most likely need new cables and a front brakeline.
Buckhorns are an interesting choice, have you ridden with them before?
I ask because I removed the buckhorns from my bike due to comfort issues.
They have a classic look though.
I'm in no way trying to bash your choice so please don't take my questions wrong.

 

Once a long time ago I road a friends sportster which had buckhorns. I have noticed in many catalogs bars that are called buck horns that all look different. I'm looking for ones where the grips are almost parallel to the bike, which I think was the classic stortster style.

 

I can't help you with the throttle and clutch cables length, you have to measure it, if it sits about the same height as your factory pullback, I can't see why not. If you want to run internal wiring, most likely you have to extend them. Here is how I did mine, install the handlebar and riser, sit on your bike and find the best riding position, tighten up the clamp so the bar stays on. Put the left and right electric control on, position them, once you get the right position you like, mark them. Take them off, drill a hole on each side so they line up the wiring. Cut the connector right at the end, run one wire at a time through the hole, before you do that, you may slide a rubber grommet on the wires, when the job is done, push it in the hole so the wires will not rub in the bar and cut in the future. I gather all the wirings in the center and make a bigger hole, they joined together and routed to the bottom of the tank. It sounds like a lot of work but it looks much cleaner. By the way, I solder all my wires and rubber shrink wrap them.