What is the differences, exactly.

Check out BAM's website...tons of great info and a chart on Bravo drives.

upper gears, all the rest are the same.

XZ has a helical cut fine tooth upper. XR has a coarse square cut gear.

Also XR gears are net forged to handle more power and XZ gears are near net forged. If you have over 600 hp, I would suggest going with XR gears only.

I was told that Merc had discontinued the regular Bravo upper gears and that now when you order a gearset from them, the XZ gear is what you get. Can anyone verify this?

do the xr gears fit in the xz. are the cases and shafts and bearings the same?

Yes all the parts are interchangeable as long as it is a newer (aft 2000 prod) drive.

Whats the status on your new gears ?

Yea, what's the status?