Caption: Before GO Transit started up in 1967, the eight unique HEP-equipped GP40TC units GO ordered from GMD London were used in break-in service on CN freights, often times with CN units too. They were painted slightly different than they would look in a year: an all dark blue "stealth" paint version with white CN logos and numbers, no white cab or frame highlights, and no large GO logos on the long hood. Shown here is a rare look at "CN" 601 at Toronto Yard in 1966 (later renamed MacMillan Yard), with another sister GP40TC visible behind SW1200RS 1318.

The units would be touched-up before entering GO service, with white paint applied to the cab, front logo panel and frame, and new GO logos and numbers would be applied. All are still in service with Amtrak as rebuilt GP38H-3's.