2,000 RPM test speed (at the drive pinion) of a 3+shunt starter, times the 3.5:1 gear ratio, = armature spinning at 7,000 RPM. 2,950 RPM on the small-coil 4-series starter = armature at 10,325 RPM. And 4,350 RPM on the large-coil 4-series starter = armature at 15,050 RPM
