In 1971, the Soviet Armed Forces began investigating the possibility of an updated BTR-60PB redesigned to make the vehicle more compatible with the BMP-1 in terms of tactical training. This resulted in the development of a BTR-60PB prototype essentially converted into a wheeled infantry fighting vehicle, designated "Obiekt 50" or "GAZ-50". Despite retaining the original BTR-60PB chassis, the GAZ-50 incorporated several elements of the BMP's design, including similar seating arrangements in the passenger compartment. The revised internal layout reduced the number of passengers to nine. New hatches were also provided for debarking in the lower hull, between the second and third wheel stations. Other modifications included a slightly thicker hull, increased power-to-weight ratio, and additional firing ports. Another feature retained from the BTR-60 was the twin-engine arrangement, although in the "GAZ-50" torque produced by the right engine powered the first and third wheel stations, while the left engine powered the second and fourth. This alteration was to allow the vehicle to continue moving even if one engine failed. The prototype was armed with a turret resembling that of the BMP-1, incorporating the same 73mm 2A28 Grom low-pressure smoothbore cannon.