What is the difference between the Bravo XR and XZ? Pros's and Con's? Max horsepower ratings?
Thanks in advance.
-Chris

XR has straight cut gears, they both use the same lower. Not sure of horsepower ratings other that XR is sold to handle more.

Can a standard bravo be updated with these gears, or is it in the housing also? If in the housing, can a XR bolt onto a stock bravo transom assemblyor is this different also??

Yes a standard Bravo can be upgraded to these gears. I have a set I might sell. I was going to upgrade my drive, but got a great deal on an XZ.

I was talking about the XZ gears they have a thicker floor. The XR gears require machining of the case.

xr's are rated for big horsepower.xr's are alot stronger

Dock Rat & del sol

You might want to check with Mike Mays at C.P. Performance. He set up a standard upper Bravo case with XR shafts/gears and an internal "power tower" for me that I keep for a spare. This does require some internal machining of the bravo case. Not cheap but supposed to handle big H.P.! The gimbal bearing needs to be changed to the larger XR bearing, otherwise everything will bolt up to standard transom assembly and lower housing.

So, other than perhaps a little more noise from the straight cut gears, the XR is the better choice.

To make a long story short, I'm wondering how long an XZ will live behind a Whipplecharged 500Efi. Single engine application if that matters. 30P 4 blade 1.50 ratio.

The XR will definately handle more power. Life span of either will depend on the weight of the boat and how you drive it. I put over 180 hours on Bravo 1's on my 311 Formula pushing 600 H.P. each without any problems. I guess I was lucky, but I always kept a spare upper on the shelf to ward off the evil spirits!