Can the larger diameter XR style propshaft be installed in a standard 1996 model Bravo outdrive? What all is required?

Yes, there is a propshaft upgrade kit, PN 840377a1. We sell it for $1130

http://www.mercruiserparts.com/partsByNumber.asp

9 Lives,
What are your reasons for going up to the bigger shaft? I ask this question because if you are in need of the larger propshaft, then you may as well be in need of a better vertical shaft.
The Merc kit comes with new gears and just about everything on the propshaft. You do need to reuse the .105" thrust ring that is in your lower now. Replace the vertical shaft bearings and maybe the shaft itself and with proper setup you will have basically a new lower. . If you have any more ??? let me know..

Hope this helps
Dick

Dick,

That was my next question. I do have problems with twisting the upper splines on the vertical shaft also. I know there are lots of aftermarket vertical shafts of different design, I.E. torsional or otherwise. What would be the best way to solve this while still staying with the Bravo design? Their on a heavy 30' cat with 750 hp running about 1" above the bottom, on Stellings adjustable boxes, using Mercury 4 blade outboard cleavers. The boat is very fast, over 125, but the cleavers don't feel to be hooked up that well, but always thought that might be the reason that I've never had a total drive failure, (Knock on wood) just twisted shafts.

Thanks for your time.

I use Imco Vertical shafts when in doubt. I have had good luck with them. I have seen broken and twisted XR vertical shafts. I would think the constant loading and unloading is doing the twisting..
Are you running a standard bravo? I take it you are..

I generally put the Merc shaft kit and the Imco vertical shaft in the lowers that need the help.. So far so good..

hope this helps
Dick