The Riviera was always sold as a hardtop model with two doors. Power and performance gradually increased over the years. From 1966 it became bigger and heavier. For 1970 the new 455ci V8 became available but emissions regulations began to take their toll on performance. The 1971 Riviera became even bigger with new styling and by the mid-70s horsepower was much reduced. This book of road tests, model introductions, comparison tests, specification and performance data tells the story. Models covered are:- 401, 425, Gran Sport 425, 430, 430GS, 455GS, 455 Stage 1, 455, 403, 350.