That grille was adopted by facelifted 1988 model-year(2nd series,after 1985-1987 1st series) onwards,being narrower;with that design was sold since 1992(and replaced by FWD Alfa 155);could hazard be a 1.8 litre DOHC version (Alfa 75 1.8) or a 75 TD(turbodiesel),'cause I imagine too much pretentious could be a 75 2.0 Twin Spark or a 75 3.0 V6 modified as taxi(usually,Italian taxists prefer as taxi cars basic models of a range,underpowered,also for have maintenance cost reduced)