None, since there could be no conversion. A linear mile is a measure of size in 1-dimensional area whereas an acre is a measure of space in 2-dimensional area. The 2 measure completely different traits and, in line with essentially the most fundamental rules of dimensional evaluation, any try at comparisons or conversions between the 2 are basically flawed.
Acre is a measure of space. Linear mile is a distance and you’ll’t convert between the 2.