In the years leading up to the creation of the Seaboard System in 1983, SCL began acquiring the next generation of locomotives from EMD and GE. These orders included GE B23-7 locomotives in 1978 and 1980, including the GE BQ23-7 variant, of which only 10 were built and all belonged to SCL. EMD GP38-2 units were added in 1979 and 1980, and 5 EMD GP40-2 locomotives also delivered in 1980. Six axle GE C30-7 and EMD SD40-2 units were added to the roster between 1979 and 1980.