Answer:
Johnny's advice to Dally in the letter was that Dally should look at a sunset and that there's a lot of good in the world.
Explanation:
In the Outsiders when Johnny was in the hospital he wrote a letter to Ponyboy which he put in a copy of Gone With The Wind.
He told Ponyboy, " I want you to tell Dally to look at one. He'll probably think you're crazy but ask for me. I don't think hes's ever seen a sunset. And don't be so bugged about being a greaser. You still have a lot of time to make yourself be what you want. There's still lots of good in the world. Tell Dally. I don't think he knows."
