In 1937, designers under the direction of A. A. Arkhangelski began working to improve the SB even more. The aircraft received a 960 hp Klimov M-103 twelve-cylinder, V-shaped, liquid-cooled engine. The M-103 engine, created in 1936-37, was based on the M-100.
After testing was performed, the SB 2M-103 bomber was launched into full-scale production in 1938 under the designation of "96th series".
SB 2M-103 planes of the 96th series had external DER-19 bomb racks under the centre wing section that were designed to carry aerial bombs weighing up to 500 kg. The aircraft's maximum bomb capacity was increased up to 1,500 kg. DER-19 racks could house external teardrop-shaped fuel tanks with a capacity of 370 litres each.
To improve reliability, a mechanical bomb release system was introduced and also duplicated in the pilot's cockpit. The aircraft was equipped with an AFA-13 photo camera. An electrohydraulic landing gear retraction system was used, and the pilot's chair received an armoured backrest. Due to these many changes, the aircraft's flight weight increased significantly, and the airframe's structure was strengthened.
From this point on, all production SB 2M-103s began to be produced with a shielded MV-3 gun turret and an LU hatch mount with an optical sight. An inert gas filling system was introduced for the fuel tanks.
Planes of later production series had modified M-103U and M-103A engines. These engines were equipped with ducted coolant radiators located over the engine. The power unit cowling was completely changed. For this, the engine oil coolers were moved to the leading edge of the outer wing.
This SB 2M-103 with ducted radiators became the most high-speed model among production SB bombers, reaching a speed of 450 km/h at a height of 4,100 m. These bombers were produced full-scale from 1939-40, being nicknamed "Shchuka" ("Pike", as a fish) among the troops, due to the distinctive form of their engine cowls.
From December 1939 on, all SB bombers were equipped with VISh-22 three-bladed, controllable-pitch propellers.