What do you guys think about the durability difference between these two drives. The application is a 28 Pantera with a singe blown/intercooled 510. 720 HP. I have read the technical differences between the drives, but was hoping to also draw from some real world experiance.

Thanks!

XR all the way.

Thanks K4M. Wish it was that easy. The boat has a new (20 hrs) XZ on it now. The previous owner blew apart IMCO Bravo ones like toothpicks. Just wondering if this XZ is going to last or be something to be concerned with.

I will know soon myself. I know it's no problem for 600hp.
ask some of the guys in the Pantera forum

I had close to 600hp on a stock b1 90 it lasted 14yrs. just don't floor it and you can jump waves just be go at the stick, last fall I had a newer 02 b1 with a 2'' shortie wholed up great I would crank the stick full once on plane after 3000rpms it would pull fast up to 6000 at 83mph 630 or so ft lbs of tq 670 hp. had 5 hard runs on it and this march it was stolen I herd the xr gears wear faster, so now either buying a x or b1 and add a steel tower. artie ps our singles are light 4000 to 4800 where the 35s or 38s are 8000 to 10,000lbs

It'll last for awhile, depends on how you drive it and where. If your in rough water much then count on it leaving you stranded fairly soon.
You could replace just the upper and use the XZ upper as a spare or sell it to offset the costs a little. (My experience has been that the lowers live alot longer than the uppers)

Buy a set of xr upper gears and change 'em.Has worked for me so far(2years) 28 PowerQuest,650 hp,680 tq. BOB

Thanks Guys. May pass on the boat. She doesn't seem to interested in coming down on the price and it needs a lot of work. The drive was one concern. Appreciate the input.

IMHO if you have enough power to break teeth off the helical cuts gears you need to move to XR. Blower motors make torque down low and break teeth. As Bob mentioned the wise move would have been to switch to the XR upper gear set.
I have seen 600-700-800- and even a procharged 1000hp motors in front of B1's and they have lived. Way too many variables to discuss between the different boats and motors. And I have seen 500hp break drives.. So it can be done, but driver skill and knowledge is key, on the right boat.

D*ck

XR's gear sets are straight cut and Slower (tend to wear faster). XZ's are helical and are naturally weaker but are faster. I screwed up my original post, got them reversed. Thanks t500hps