Running left handed is hard on the top cap of the drive. If its something that has a bunch of power might want to upgrade to a billet top cap....

yea a drive shower and billet cap

Its stock 454 with exhaust and an intake.

You will be fine,,,,,, every boat with twins runs one backwards

Here's my story.....could be a total coincidence.

Ran a 525efi/Bravo XR with a RH prop for 200 hours. Decided to try a LH, the results where favorable but after about 10 hours my drive self destructed. I'm wondering if the gear set develops a wear pattern after a while and switching rotation is what killed my drive. I broke a tooth in the upper gear set, and broke a stud off the top cap.

Most likely what happened IMO.

I know a lot of people and shops that will swap drives L/R every season for even wear,,,,, not my personal choice

I wouldn't see the wear pattern being the issue cause you are running on the other side of the gear. I could see that changing direction on all the bearing might begin the failure...

you can't run on the other side of the gear. you would need a counter-rotating engine to do that. the-i guess it is the pinion gear-the one that the engine turns is always spinning in the same direction. the same face of the gear pushes on the teeth of either the rev or forward gear. the only diff is which has the heavy load of forward compared to reverse with much lighter load. using reverse gear for forward isn't stressing it the other way, it is just stressing it more, while forward being used as reverse is getting a rest. now, as to torque steer. if the prop turns the same way as the engine, both sets of torque will push the boat over the same way, causing an apparent list. prop turning opposite engine direction somewhat cancels both out. actually it should cancel completely, cuz the engine torque is pretty much equal to the prop torque.

Dave M - Most likely the top cap/stud failed or loosened first then it took a tooth when the gear stack became unstable. Its always good to check the tightness on the top cap bolts and condition of the cap on a routine basis.