I ran an X drive with about 600 HP for 700 hours before I noticed a small amount of metal in the oil and could detect a high pitch noise that was new. Went back to my old B1 as a backup before anything came unglued. I did have some good power in front of it but on a fairly light hull in comparison to what some are running, Baja Force 235.
Back when I made the decision to go with an XZ vs an XR longevity was my concern. XR a little stonger but probably weaker when you have a lot of hours on it. XZ a little easier to break with high HP but hard to wear one out.

So then~350 hrs with an X1 1.65 drive and a B30 running the piss out of it and did not break the X1 upper gears but failed a shaft. That sounds pretty encourging for X1 upper gears and 600hp versus the current XR gears at least for the 1.65.

Is your XR drive a 1.5 or 1.65?

XR 1.5 They don't make a 1.65 XR.

1.65 ratio is more of an "altitude" thing..

700 hours with X1 gears and 600hp. Excellent! What is the XZ's drive ratio? What prop did you run for that 700hrs?

1.5 with a 27 Mirage Plus. Just took it easy on it and did not feed it much boost until up and on plane. I think one of the reasons it lived so long was my drive cooling. I have a Simrek (?) drive shower. When I had a supercharger I installed a crossover with a home made pressure relief setup that consisted of two valves, one blew off at 7 psi and the other around 14 or so. The discharge for these were T'eed into a 1" fitting that exited the hull above and center of the top cap. A HUGE amount of water is being discharge to the top cap a via the drive shower. The water would hit the top cap and splash back up against the underside of the swim platform and in general splash anything exposed back their. After hard runs you could not detect any real temp difference on the uppers vs cruising. That and 25 hour oil changes probably helped it along. I did break my XZ in with a 21 pitch prop for 10 hours then took it easy for an additional 10.

Very good and encouraging info. My hull is 3700# same as yours. My drive temperature during extended WOT running is 270F+ with the factory installed drive shower (not very good one). I ordered a Simrek Halo MAx drive shower last week. I had previously tried a temporary 5/8" hose sea water bleed off from the closed cooling sea water system dumping onto the top of the drive but did not seem to help much.

What drive lube did you use?

Didn't you maintain the 1.65 final drive ratio with the XR by using the appropriate lower drive gears?

What kind of a drive shower do you run?

No - I've owned 3 drives by this time (2 x 1.65, 1 x 1.5).

The Latham 5/8" shower that goes into dead center of top cap.

Im just asking a question im doing a major upgrade in power and was wondering if i bought all the parts that are in this upper is it a good idea. I have a 35 outlaw with merc 525 with stage 2 whipples boat weighs about 9000 with fuel.
http://teaguecustommarine.com//store...roducts_id=936

You're buying all the same parts that are in the regular XR. Teague doesn't make any gears or the like. I personally think the IMCO SC is a better choice than Merc anything in this size/capacity. I just spoke with them about a possible better alternative for mine.

Same gears. The newer XR has addressed all the same characteristics of the Platinum Drive. Better top cap... They were not able to explain to me how it's any better than what I have. Perhaps I got the wrong guy; I don't know about that.