9 tails chakra create the Kurama's whiskers =>
Ginkaku and Kinkaku were not Kurama's jinchuuriki, they ate his flesh and his chakra.
Kushina was Kurama jinchuuriki but her chakra was powerful enough to avoid the process, Naruto's chakra and Kurama's chakra melted before he was born, later they both agree to mixed it even more.
he now has it in is dna probably and passed it to Boruto and Himawari but not entirely (only 2 lines not 3 likes him and the twins).