Convert from block [East U.S.] to legua [Spanish, pre-1568]

Unit Definition (block [East 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 in Eastern USA is about 1/20 mile or 80 meters.

Unit Definition (legua [Spanish, pre-1568])
Unit 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.