Gra – Acceptance not complete even in Vilna

Igros Moshe (OC V #24.6) In situations where the Gra disagreed with the prevalent custom even when Ashkenazim agreed with the Sefardim, the poskim of his generation agreed that since he was much greater than the other poskim of his genersation even though they were also very great and he was also greater than the poskim even of many previous generations and therefore he had the right to disagree with them Furthermore all his students who were also gedolim in that generation agreed that the Gra could also be viewed as authoritative as a Rishon Since he was the latest posek the halacha should be according to his ruling  People started accepting the Gra’s rulings in all matters even against the accepted custom. A great man and genius like the Gra is able to make changes even for Sefardim even against the rulings of the Rambam, Rif and all other Sefardi Rishonim. However no other Gedolim of the Achronim are able to do this. Nonetheless the customs of the Gra were not accepted by everyone even in Vilna and they were not insistent that his customs be observed