I'm installing a 7" bottom mount headlight. The wire loom with the bucket was not as long as the stock loom so I swapped the stocker into the bucket. All I have to do is get the nerve to drill a hole in the lower triple clamp for the mount.
I've read a post somewhere that there is a flat spot underneath the custom's lower triple clamp. The three that I inspected on the dealer floor not only didn't have a flat spot as part of the casting, they didn't have a counter-bore for the Allen head screw either!
Should be done later today.

dont know about the later ones, but on my 02, i had to drill out the lower triple tree for the headlight mount also. on the underside of the tree, there was a 'high spot' or ridge type affair... the metal is very soft and easy to drill, my only suggestion is to take the fork tubes off, separate the triple trees, and drill it out on a drill press. it isn't very difficult to take the front end apart. if you don't want to go that route, at least take off the front wheel and drill from the bottom up. i didn't do that and the hole ended up being slightly crooked, which wasn't a big deal because of the adjustability of the headlight, but it didn't allow the headlight mount to sit flat on the tree. luckily for me, when i bought a new set of fork tubes (gotta love the 'bay) they came with a set of trees attached, from a custom, with the hole already drilled :banana

I guess I don't do any thing the easy way.
I bought a 3/8" right angle drill, used my home made drill bit guide and let the chips fly. I ended up with a perfectly centered and plumb hole. :clap
What I had to wait on was the arrival of a counter-bore/spot-face tool to give the underside of the allen bolt head a flat surface to seat against. It has a pilot to ensure the spot face is located correctly. The triple clamp is still 3/4" thick as measured at the spot face to upper surface.

Do you have a pix for us to see. I'm thinking of a 7" for my XL1200R.

Mine....

http://i49.photobucket.com/albums/f260/preacherspulpit/WideGlide/Mockup3.jpg