Not to high jack but while we are mixing and matching parts. Heres one to keep in the back of mine. Back in Oct. someone asked me if I had any Used XR prop shafts as the prop shaft on his freinds Skater broke off at the carrier. To make long story short he stopped by with boat and it had Konrads on it. Pulled the carrier out on boat and prop shaft are not even close. He said he had to run the boat the next day So I stuck a XR shaft the old style .200 thrust washer (the kind used with shims) his used load ring and a XR carrier in. I had him in the boat turning input while i tightened carrier nut, all seemed to be good. I saw him the next day running over a 100 mph for a couple miles and all was good, boat is still running. So I guess it works.

Why?

The XR lower gears are the same gear as the B1, but has a larger ID at the beginning of the bore to accept the splines that are larger at one point on the shaft. The splines that do the work are the same size as the B1's. The main reason for this modification is because the B1 gears are less expensive than the XR lower gears. Unfortunately the only ratio that this applies to is the 1.5:1 (15/19) gear set. I don't see a listing under the B1 for the 15/17 or the 17/18 gear set.
Hope that helps.
Dick

Seems like a lot of work for a 50$ difference. Just my 02

Not if you have bravo 1 gear sets and some xr shafts laying around.JOHN SR

true.