Bearing retainer sizes

Hope I'm not too late to the party. Just turned 55. I've been absorbing a833 knowledge from the threads in this forum so thank you. I have a slant with an 833od and it still works but needs rebuilt. However, before I remove it, I want to source and rebuild or buy ready to install another 833od to keep down time to a minimum. Or maybe find a regular 4 speed with the 2.66 1st gear that will go in with little fuss. Apparently that will require a bearing retainer adapter. Thanks for that tip also. Thank you FABO for all of the info.