Despite the original intention to incorporate as few changes as necessary to the basic design, the GAZ-84 works had to make some 1,293 engineering change orders to the original Douglas drawings, involving part design, dimensions, materials and processes, most as a part of metrication of the design from U.S. customary units to suit Soviet standards, no small task for Vladimir Myasishchev to accomplish. The well-established Shvetsov OKB-19 design bureau, responsible for the great bulk of the Soviets' air-cooled radial aviation powerplant designs of the 1930-40s, used their Shvetsov ASh-62IR radial engines, a Soviet development of the nine-cylinder Wright R-1820 "Cyclone 9", to power the PS-84. The same Wright Aeronautical "Cyclone 9" radial also powered the earliest Douglas DST "Sleeper Transport" versions, and initial 21-passenger versions, of the original American DC-3 airliner.