This place probably has it

Click on the Chevrolet part on the main page and its under transmission and then gear shift parts. Should be the second item pictured. It won't let me link directly to the page... I haven't ordered it or taken apart my floor shift 3 speed so I'm not 100% sure its the part you are looking for but its my best guess. Not to high jack your thread, but if you are doing a rebuild did you order a kit or just going to a bearing shop and matching the bearings from there? I'm planning on rebuilding mine pretty soon and am looking at pricing parts.