Depending on horsepower you put to it, yes the XR models are one of Mercruisers stronger drives internally for the bravo models. If you are wanting more serious power like 570+ HP, then there are a few aftermarket companies that have done their homework and made them even stronger to hold up better under a bit more horsepower over the stock units. They seem to do the upgrades more for the bravo one's as they're more popular for "speed boats" but they'd be able to upgrade the B-3 upper unit for you just the same. http://www.mercuryracing.com/drives/bravothreexr.php
Thanks! I'm considering a re power , new engines, out drives. The MerCruiser 4.2 diesel with B3 XR or Volvo Penta D4 with DPH out drives.
My 41A's are getting tired . Also looking at Yanmars with Hamilton jets.