This seems to be a good place to start my questioning.
I want to put a DNA trike kit on my 08 Road King, and was told I need a 139 tooth belt(factory unit is 137 tooth x 1" wide). I am having a heck of a hard time finding a 1" wide 139 tooth belt, BUT, I have been told I can use a factory 04-06 belt, which is 1-1/8" wide, because the DNA kit rear pulley will go up to 1-1/2" wide belts, and the front pulley on my bike, which uses a -06 part number, can actually accept the earlier belt, and I will be good to go. Has anyone done this to verify if this is true, and I can use the earlier belt? It would save time, and obviously, money, and this will go much smoother for me and my wallet.
Thanks. Cricket

Well, for anybody with the same issue, here is an update.
The DNA kit can use an 04-06 belt (40024-04B) , which is 1-1/8" wide, and 139 tooth length, OR, if you want to stay with the 1" wide belt, you can use the 04-06 CVO belt (40040-05), which is the original (07-08) width, and 139 teeth, making it perfect.
I list this, because they are available on eBay used (yes, I will use a used belt, if in great shape with low miles), or from the dealers, if you want a factory belt.