I'm not sure specifically which 'Martin Luther King stroller story' you are referring to. There could be various stories related to Martin Luther King that might involve a stroller in a creative or symbolic way in some local tales or interpretations.
The length of a soloist stroller story depends on a lot of factors. It could be a quick tale of a few thousand words or a sprawling epic that runs into tens of thousands. It all depends on the plot complexity and the author's style.
Well, if 'phil' is part of 'pulp fiction', it might be a unique term or name within that context. Maybe it's a nickname for a character in the story. But without further information, it's hard to determine its exact significance. It could also potentially be an abbreviation for something relevant to the movie's plot, setting, or sub - culture.