Without a time frame to work with your question is pretty hard to answer. You might think through the “when” and ask the good folks at the New York Central Technical & Historical Society. In general diesel era terms, local passenger equipment varied north and south of Croton-Harmon, NY. South into NYC was pretty much all electric m.u. equipment. North to Poughkeepsie & beyond could be a GP7 or two and some coaches or one or two RDC’s, depending on the year in question.