I think your engine has a four point mount system. Shimming one of these four points MIGHT help align the drive. Might not too...but I would say if you had a failure before, you might again even with the better coupler.
Shimming the front of the motor would cause the tail end to drop, and the opposite with the rear of the engine. If it is set too high to start...you are right...that is a problem. But it seems worth the time and effort to pursue if it keeps the engine/drive and coupler happy. Must my .02...
Dr. Eagle, good points. I will give that a try. Thanks, R/R