Convert from vara [Texas] to microinch

Unit Definition (vara [Texas])
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 (microinch)
The microinch is a common imperial unit of distance equal to one millionth of an inch, or 25.4 nanometers (nm). The microinch is used for precise machining tolerances and also to describe the roughness of surfaces.