Box Chevy Caprice Classic on 26-inch dub wheels

What type of car is a box Chevy?

What is considered a Box Chevy? What year did the Box Chevy come out?

A Box Chevy is a 1977 to 1990 Caprice Classic or Impala.   This is the only year of car that is considered a Box Chevy.  The designation is not a blanket statement on every car from that time frame just the Chevrolet Caprice and Impala.  

Box Chevy Caprice Classic LS Brougham on 26 inch MTW wheels