I recently read Coaster 2's excellent Yakima and was impressed with the way the author used internal monologue. I then read a criticism of the story for too much of this and not enough dialogue.
When I read a first person story (past) that is heavy on dialogue, I usually wonder if the narrator has an eidetic memory (I guess every character in fiction has this, lol). To me this just does not ring true. It is easy for character narrators to report what they thought and how they felt at a certain point, but not necessarily remember what they said or had said to them (unless the scene was particularly memorable or it was an important conversation).
The other thing with first person story telling is that it allows the narrator to share his/her most intimate thoughts with the reader without having to "show" the reader by having to force a piece of dialogue (like the famous "tell the bartender your woes" cliché/mcguffin or some other father confessor type).
I thought that Coaster2 gave us just enough dialogue to keep it interesting, while keeping the narration heartfelt and believable.