The GP30 was conceived out of the necessity of matching new competitor GE's U25B. The U25B offered while EMD's GP20 and its 567D2 prime mover was only rated at . The U25B also featured a sealed, airtight long hood with a single inertial air intake for electrical cooling, with a pressurized cooling system which kept dust out of the engine and equipment area. Finally, the entire GE design was optimized for ease of access and maintenance. The U25B demonstrators were receiving much praise—and orders—from the railroads that tested them. Meanwhile, ALCO had been producing the 2,400 hp (1,800 kW) RS-27 since 1959, though it had not sold well.