From your description you have two different entities. A partnership that would file 1065/565 for part year and mark itself as final.

The new LLC (with a new fein) will then file a 1065/565/568 for the remainder of the year, assuming it is not doing any other election then the default partnership. It will also need a state of CA registration number. https://llcbizfile.sos.ca.gov/SI