Saab Safir 91A to the right and the 91B to D model on the left. Here you can clearly see the difference on the engine type. The 91A to the right with a radial 4 cyl 125hp de Havilland Gipsy Major engine and also some of the 27 manufactured units had the 145hp Gipsy Major GM10 engine. Much smaller nose section on these earlier 91A aircraft.
The 91B to D models was equipped with a boxer engine, 6 cyl 190hp Lycoming O-435B on the 91B and C models and a Lycoming O-360-A1B on the 91D model.4cyl 180hp