Xbox live gamertag recovery?

Hi evryone, I’m 14 years old and have moved from Alberta, Canada to Pittsburgh, Pennsylvania in the states. We are getting a new Xbox 360 and I would like alot to have all of my achievements and unlockables on games still unlocked on the new 360. If I brought the old 360’s hard drive and put it on the new one, would that save everything? For example my armor perms and rank in Halo 3?

If you bring your hard drive with you, you can throw it on the new xbox and have everythign halo rank and any halo maps you bought. Or you can just recover your gamertag on the new hard drive by putting in your email and password, you will have all your ranks but any maps and other things you bought on the marketplace you will not have. Have a fun summer, and happy gaming!