Michael, I do not believe there is a BOP connection. Impala body style only corresponds to Bel Air, Biscayne, or Caprice. All Chevrolet. For '66 it would be '65-'66 B-body would be '91-'96 Caprice or Imp/SS
GM big cars had unique frames to their division until 1971. A Buick LeSabre might be its cousin, but short of window glass, darn near nothing interchanges.
Woodie said: What body style is a 66 Impala 2door? Is it a b-body, and what BOP's correspond??? That's a B body car.