Please read these two sentences aloud to get the full effect.
"I walked the entire sixteen blocks," Harlan blurted out.
"I walked the entire sixteen blocks," Harlan said.
Did you notice the emphasis? In the first sentence, "blurted out" grabs your attention and you become aware of how Harlan spoke. Nothing wrong if that's what you want readers to get.
In dialog, when I want the emphasis on what's said,
I use one of the invisible words of attribution.