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

Unit Definition (vara [South America])
Vara is an old Spanish and Portuguese unit of length. Varas are a surveying unit that appears in many deeds in the southern United States, and varas were also used in many parts of Latin America. It varied in size at various times and places; the Spanish unit was set at about 835.9 mm in 1801. At some time value of 33 in (838 mm) was adopted in California, and 33 1/3 inches (847 mm) in Texas.

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.