Gas up your hippie van and breakout the tie-dyed tank tops, because The Grateful Dead is about to make a comeback—sort of. The legendary jam band has some unlikely fans in some of indie rock’s biggest groups, and now, several of them are working on a tribute to Jerry Garcia’s rock outfit. In an interview with Radio.com, the guys in The National admitted that they are proud Deadheads, and have begun organizing a Grateful Dead tribute album, with proceeds benefiting the non-profit Red Hot Organization (a charity that fights AIDS). They said that so far, a handful of other artists, including Vampire Weekend, Bon Iver and Kurt Vile have signed on to contribute Dead covers for the album, which is expected to be released sometime in 2014 …