Some units for the GM&O, MILW and SOO were built with from ALCO trade-ins and ride on ARR type B trucks instead of the standard Blomberg Bs. An indisputable tribute to the quality of the GP30 design is the fact that a good number are still in service as of 2015, which is a service lifespan of over 50 years and well in excess of the design life of 25–30 years for the average diesel locomotive. Furthermore, when life-expired, some railroads chose to give them major rebuilds instead of scrapping them.