[eschaider]

Rather than cobble together a compromise solution, why not get the measurements you require (sounds like you already have) and then head out to your local job shop machine shop. Have him make a single piece silicon bronze bushing for you that fits the crank both in its diameter and also depth but also gives you the additional length you are looking for to support the input shaft.

You will be modestly more expensive than the store bought and user modified bearing solution and much more functional and durable..