I'm trying to find a reincarnation fic I read when I first got into the fandom. Sam had been Sam Colt in his last life and Dean had been the hunter who introduced him to the supernatural. When past Dean (I think he was named Jensen) died, YED made a deal with Sam to bring him back if Sam made him the key to hell (the Colt). Sam was sleeping in the Impala and he dreamed his memories from his life as Colt. Dean freaked out when Sam woke up and started talking about being Colt but I believe he had remembered as well by the end of the fic. Anyone recognize this one?

Found! It's Stand by you by tempestquill