For the most expensive thing possible, scroll down and click on "service parts":
https://www.holley.com/products/discontinued_product/parts/0-4224

Or save $200:
https://allcarbs.com/product/holley-660-center-squirter-rebuild-kit/

The generic AED kits have always worked great for me. Always extra parts included which I appreciate.
They may lack the seals for the fuel transfer tube but the rest should be included.
https://www.aedperformance.com/parts/rebuild-kits.html