I run outboards and I've put nose cones on. They're pretty similar to an alpha, shape wise. If you're looking for process instructions, you may want to look here. (http://www.carlsonspeed.com/forums/i...p?showtopic=49)
If I were you, however, I'd try to get a handle on other people's experience before I did it. On an outboard, a cone will slow you down a wee bit below certain speeds.
It looks like a cone would reduce drag at all speeds but it obviously doesn't. At least, not on an outboard.