From what I understand, a Yuengling can is the best. I volunteer to provide one.

On a serious note, I am currently using a 26.4 Cinelli stem (I've never heard of a 26.2) with a 25.4 bar.
The shim is cut from an old sleeve and it looks really thin, until I try to put it in, and then, though it made it OK, it looks huge.
The gap of the stem where the triangular gasket fits is way too big, so I've got to go to plan E.