Naruto gets promoted to chunin along with Shikamaru after their first chunin exam and gets moved to a new division in the shinobi corps where he gets placed in one of their teams. Not Anbu... I feel that the Konoha 11 continued to work together cause they were the main characters and from a story point of you, it would be stupid to give Naruto a new team and forget the old characters. But realistically, I believe letting Naruto work with a team of chunin will help him grow into his role quicker and the same for Shikamaru.
This will cause many things to go different from canon and this will be completely AU.
The new team: All four are chunin Team leader: Most experienced. A few years older than Naruto Medic: Third member: Fourth member: Naruto
Everyone will be between 12-16 years old with Naruto being the youngest and the team leader being the oldest.