Does anyone have a ballpark for parts and labor to do this conversion? I'm starting with a '04 Bravo one X with 400hrs, unit performs great. In looking at the parts breakdowns it appears there are a fair amount of common parts like the vertical shaft, housings, etc.

Thanks!

Dude, if you have an X that is in great shape at 400 hours STAY WITH IT! Break it open and replace the upper gears if needed. You'll never get half the hours out of a set of upper XR gears. Plus XR's will eat a tad bit of speed and they are louder (heavy gear noise). Some people are seeing better performance out of X drives anyway.

Keith thanks for the reply! Do you think a freshened X drive can handle 600+ HP in a single 28'?

Awe jeesh, here we go. I have had gear pitting issues on XR's ever since I went to them with my 600's. With both stock new and cryo treated gears. There will be a hundred opinions and science behind both. For example, there is more gear surface carrying the load with the X gear tooth but the base of and XR gear tooth has a thicker base. I have a hard on for hatred against XR gears. But, my vote is still for the X gear set. Lets see how everyone else chimes in.

In the reading I've done on here (and many posts from you Keith) it does seem there is a difference of opinion on XR gears. Max Machine in Havasu said there were some bad runs of XR gears for a while, but now things seem to be better.

Also for clarification, my X drive has 400hrs behind a stock 496HO. I just dropped in a 600+ HP whippled engine so I need to do something. I'll be running a bravo 4 blade likely 28 or 30P with 1.5 gears on a Nordic Heat 28'.

Run it until it blows and then swap in a new XR upper. Have towing insurance if boating offshore.

Why not just bite the bullet and go SCX upper with an XR lower? Seems like people have found this setup to be more reliable and cost affective after a year or two. I have a single 28 Pantera and I am on the hunt for an SCX upper. I don’t want to have drive issues running the boat when I’m out. Time is more valuable.

What is the cost of a new SCX upper and new XR lower?

Around 15K

An all new SCX with an SC lower will cost about $17,900. You would never break it at that power level. If you are intesteded I'm going to have a freshly rebuilt IMCO SC-3 inch shorty complete drive for sale. It is not as strong as the SCX but will hold up better than the XR for sure.