The 02 and 06 FLHR and FLHRCI dashes have the same center-to-center from the acorn nut to the lower screw hole for mounting. But if the Road King Custom dash acorn nut mounts an inch higher, I'll be there are 2 mounting points to put the top stud in the fuel pump canopy.
I JUST (today) put one on a 2000 RKC... this e-bay seller has a smokin deal for the whole shebang. Go to ebay and plug in this item # 4607774896. The whole thing is a straight bolt on EXCEPT the inner speedo retaining ring. The one that comes with the kit didn't work with my 2000 speedo. Perhaps the Road King Custom speedo is different...I don't know. I took my 2000 ring to my grinder (its plastic) and got rid of the 2 tabs that didn't fit inside the new housing. The only thing that some of you may not like is the speedo's retaining ring had a tab that engaged the console...it's function would be to prevent the speedo from rotating....well, I lopped that off. The rubber gasket, along w/ the retaining rings "clips" seem to hold it tight enough to prevent that. Everything else is strictly bolt on w/ complete instructions. Came complete w/ gasketed screws for top of gas tank (which changes the top retaining bolt position)....other than the speedo issue....easy, easy, easy.
If you're interested this part had a Buy-it-now...so you better step on it!!! I've seen them go for at least75 bucks more...