Convert from block [South, West U.S.] to legua

Unit Definition (block [South, West U.S.])
The Block is an informal unit of distance popular in the U.S. A block is the average distance between street intersections in the rectangular street grids common in most American cities. The length of a block is about 1/10 mile (160 meters) in USA cities in the South and West.

Unit Definition (legua)
nit of area used in the southwest US, equal to 25 labors, or 4428 acres (Texas), or 4439 acres (California). Also, a unit of length-- approximately three miles.