Cam bearing failures are usually caused by someone overtorqing the holddown bolts. As far as being as reliable as an ATK if you do the z400 rod bearing you will be one step ahead of ATK because they have not done this update on thier quads yet. In fact there are many updates developed by the Cannondale R@D team (owners) that has left everybody else in the dust.
Goto cannondaleriders.com and look up all the latest tips and updates.

 

My buddy has a 250r motor in his. Very awesome but very expensive to do it right. There is not as much room as you think in that frame. We will be in Little Sahara, OK. on Sept.16,17, and 18 with the bike.

 

Send the motor to Wisetech. He's close to you and he'll get it done right, THE FIRST TIME!!