This context comes from the novel "The Shining" by Stephen King
"You could have a police car in five minutes and a fire truck in level less time than that, because the fire station was only three blocks away and one block over."
I know what "a block away" means.
A block is:
- b. A segment of a street bounded by consecutive cross streets and including its buildings and inhabitants.(American Heritage® Dictionary of the English Language)
it's basically one side of:
a. A usually rectangular section of a city or town bounded on each side by consecutive streets. (American Heritage® Dictionary of the English Language)
So "one block away" would mean on one of those segments of the street which is divided by a cross street once in any of the two directions. Two blocks away would mean that we have to cross(the cross street) twice. But what does "block over" mean? I suspect that it means that in contrast to "a block away" where we travel along the street(without taking turns) we are supposed to turn(either left or right), although I can't find any definitions that would support that theory.