Everyone's missing the REAL point. A few years back, Fred Kiekhafer himself pointed out (in print) that the Bravo was originally intended for just over 300 hp. In the ensuing years, numerous band-aids and improvements have been made to increase the drive's strength, but the bottom line is, in almost all performance applications, the Bravo is being used for far more power than it was ever intended to handle. That's why when one problem is fixed, it breaks at the next weakest point. Mercury never designed a drive to handle go-fast power over 500 hp until the NXT. In the meantime, no one was interested in installing an overkill $25,000 #6 drive.
In short, there should have been a "Charlie" drive to handle 500-800 horsepower, but Mercury Racing didn't have the $$, and Mercury Marine didn't need the capacity. The net result is that Bravo owners have served as the development fleet for Mercury, spending countless hours and dollars on both successful and insuccessful upgrades. The bottom line is that the Bravo is simply too small by about 20%. It's like using a Pinto transmission in your Corvette. It's inexpensive, it's low drag, and it will work most of the time, but there is no room for error.