on a 29' fever what engine do you switch from a bravo 1 drive to an xr drive & on a hp 500, 525, 575 motor what kind of minor mods can be done to increase hp & mph. what kind of mph are we talking

Switching lower housings can gain a little speed and may be go up one prop size. A switch from a lower water pickup lower unit to a standard water pickup lower unit can do this. But is the cost worth 1 or 2 mph.

what year of a 29, what motor/drive (motors/drives)setup do you currently have, what prop(props) and what mph at what rpm are you currently seeing........doug

Switching lowers is a zero sum gain.
500's/525'2 is a non issue for Bravo 1 or X.
Decide what you are going to use for power.
Drop that dime, then the drive question will be easy.
Bryan