The bike is a 2005 Ultra Classic

I've just got hold of a set of Harley Davidson FLH 2" Pull Back Bars.

They are wasted on the underside designed to be wired externally, but I would like to wire them internally is it possible to drill through the wasted area of the bars and wire them internally.

Has any one done this to bars which are designed to be wired externally?
Can anyone tell we the measurement as to where to drill on the underside?

Thanks in advance.

Markie.