I found another thread on here that linked to this thread:
Leaking CV Boots - Repack and Clamp - Articles
Where the author had the same problem with the OEM 74 clamp, and went with another style, but unfortunately it doesn't have a part number...
Edit; following the rabbit hole, it looks like this might be it:
https://www.belmetric.com/cv68-cv-boot-clamp-p-1006.html?zenid=kckcjipsb70epti7ihm7o5p910&cPath=15_841