This is one of my biggest grips with boats. the only performance vehicle I have ever had that that has a drivetrain made of glass. Even with big expensive drives they still break and are just crazy money for what they are. The price a #6 is it should be bullet proof!!

I went thu a regular bravo in a month (600sc) and a built XZ in 12 hours the first 11 hours breaking it in and babying it. (25'boat)

A 29 Fountain Fever is a heavy boat for a single engine, a lot depends on what pitch prop you run,
a good friend of mine runs same boat w/525 EFI, it works hard to get on plane w/a 26 Pitch Bravo1 prop, he ran a 28 pitch couple months and it took 1/4 mile to plane at WOT., it finally destroyed his Bravo XR drive w/120 hours , he runs 75-76 on gps w/the 26 pitch, my point is you can't run more pitch prop or you won't ever get on plane no matter how much power you have,
Last year someone installed an Ilmor 625 in same boat, last I heard he was only running 77-78 on gps, I don't know if he was able to get more speed , haven't heard about it for a while .

On a lake or on the ocean?

When Im heavy on lake running I get double the life out of my XR.

UD

If yours only lasted 3hrs pushing a small boat like that with that hp your doing something way wrong. This boat has all ready been a 600hp boat for the past 3yrs and as far as I know original drive. It last all summer and I defiantly beat on it this summer. Shootout weekend at loto is rough. Ive talked to people and this is all over the place. One guy says I'll break it in 3hrs then there's other guys on here with close to 1000hp and been going three years.

TGM you are correct, it has a lot to do with the driver and how he takes care of his equipment, ,,a Bravo1 will take a lot of abuse,,,, just don't overload it with a real heavy single engine boat ,,,then add big power, ,, then run too much prop so it can't get on plane without taking a beating every time you start out.
My friend tried that with his 525 EFI w/28Pitch, and destroyed his ,XR ,drive in the 29 Fever, he wanted to run 80 mph, problem was he beat it to death getting on plane.

+1 I have heard many horror stories of guys that put on shorties lowers searching for the last mph only to beat there boat up trying to get on plane resulting in short lived bravos. To each there own I suppose.

The absolute #1 killer of drives is rough water.

how about a 256 blower?

Even worse. The smaller underdriven blowers make more torque down low than their larger siblings. They almost always make less HP up top though.