Shift tubes have been like unicorns for a few years now. Even when we could get them, we could not get all styles. But they were great and popular for as long as they lasted. Too bad too, because they're still breaking!@
I don't remember what year yours is, but if you have a '73, '74 or '75 you don't want a kit anyway. Too many of those (especially the '74's) have a mix of old and new parts to the extent that I just tell anyone that has one of those years to buy all the available parts and then return what they don't use. Yeah, it's that sketchy!
If yours is already apart then it's not a problem because you can see what style bearings and such you have, but if it's still together, get all parts and hope you have enough of the correct ones.
Do you need a shift tube for sure? Or were you just hoping to replace it before it was a problem? In many cases you can fix the one you have.
Paul