On Tue, 21 Dec 2004 21:46:57 -0800, "aluckyguess" wrote:

How many knots would be gained with this?

The consensus is little top end would be gained, although a few
additional knots would be possible by allowing the engine to operate
at higher power at lower altitudes.

See this google thread for a discussion on fixed pitch vs. C/S.
http://makeashorterlink.com/?Y5531281A