Why did Ponyboy and Johnny turn to Dally for help? What did he do for them?

The boys go to Dally because he will help them unconditionally.... no questions asked. After Johnny stabs and kills Bobby, they go to Buck Merril's house to find Dally, because they remember there is a party there that Dally said he was going to. Buck answers the door, clearly drunk, but goes to get Dally when the boys ask for him. Dally appears in the doorway, pretty sober, and listens to what happened. Dally has been in a fight with Tim Shepard, and has "cracked some ribs." He lets them inside when he sees that they are cold and wet, and gives them fifty dollars and a loaded gun. He also gives Ponyboy one of Buck's shirts and his own brown leather jacket. He gives them instructions to get on a freight train to Windrixville, then find an abandoned church on top of Jay Mountain.