The adaptor kit is a MUST since the oil tank on the Dyna bikes is a bit lower than the frame. If you tried to lift it without the adaptor kit, the lift pads will be making contact with the oil tank rather than the frame. That's not good!
Hope you are enjoying your '03 Wide Glide as much as I'm enjoying my '02 Wide Glide. (Of course, living in the far north, my enjoyment is being limited by the fact that the riding season -- for me at least -- has ended until the end of winter.)