SP did not, at first, place the big FM's in commute service. They were first sent to New Mexico. For some reason, they did not work out there. But they had steam generators, so they were sent to work in the SFO commute service. (SP did not use the "r".) Worked well. No SP engine could touch them until the SDP45's, and even they had to have some sort of electrical mod.
Now CNJ did buy the same engine, and they were used in passenger service from the start. But were they used in commuter service?
Now that engine in BW and TTG Harriman or bi-level coaches would make a great model!