From 1977 to 1984, the fifth-generation Cadillac de Ville series of luxobarges wasn’t particularly exciting from the standpoint of performance. The switch to unleaded gasoline translated to reduced compression ratios, and early catalytic converters didn’t help either. For the sake of reference, the 4.1-liter V8 engine with throttle-body fuel injection produced only 135 horsepower for the 1983 model year.