I got one of the Kuryakyn Chrome Kickstands in and installed on my F6b.
Held the original and the Kuryakyn up together and the length is the same, footprint is a lot bigger along with the diameter.

Looks great installed, and the lean angle appears to be the same.
Since the pad is larger it may effect the lean angle by a very small amount. Works better with my Floorboards since it sticks out a little bit more when up.