On the double roller, machine the crank gear chamfer to match a stocker. The Aussie chamfer is different. That stops the deflection that causes the crank gear to hit the oil pump cover. It's one of the things I dislike about ZZP, Zoomer was in that thread and the discussion with Rollmaster about making a US crank gear and they never changed it on their site to either be a machined gear or any other info beyond "put on a machined pump cover". Don't need a different cover, you need the chain to be aligned.
