Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
The EMD SD38 is a 6-axle diesel-electric locomotive built by General Motors Electro-Motive Division between May 1967 and October 1971. It had an EMD 645 16-cylinder engine generating 2,000 horsepower (1.5 MW), compared to the turbocharged EMD 645E3 V-16 engine that produced 3000 horsepower. Aside from the 3-axle trucks and a longer frame to accommodate them, the SD38 was identical to the GP38; the SD38 had the same frame as the SD39, SD40 and SD45. 52 were built for American railroads, one was built for a Canadian railroad, four were exported to a mining firm in Jamaica and seven were exported to a mining firm in Venezuela. The SD38 was succeeded by a Dash 2 version called the EMD SD38-2.
An M version of SD38 was built for the Brazil Federal Railways (RFFSA - Rede Ferroviária Federal S. A.).
Forty of a passenger version, the SDP38, were built for the Korean National Railroad in May-July 1967. The units were numbered 6351–6390. It was later changed to 6201-6240.