The New York Central eliminated all train names in 1967, except for 303 and 304, the James Whitcomb Riley. All long distance passenger service east of Buffalo was replaced by the vestigal "Empire Service," with all trains except 63/64 terminating at Albany-Rensselaer or Buffalo. Trains 63/64 ran through to and from Chicago via Toledo. but they only handled coaches and a diner-lounge west of Buffalo.
Train 61 connected at Buffalo with Chicago trains 27 via Toledo and 17 via Detroit, with 14 and 28 making 62 in the opposite direction. That set of trains was the vestige of the New England States, connecting at Albany-Rensselaer with 427 and 428. It handled sleepers from Boston and New York to Detroit, Toronto and Chicago. The Toronto connection was TH&B 371.
In 1969, No. 61 was scheduled to depart Grand Central Terminal at 6:30 p.m., so that was probably his train as far as Buffalo. Then he was probably on 27 to Chicago. No. 83 departed GCT at 4:30 pm, but it only ran to Albany-Rensselaer.
The PRR still had its train names at the time of the merger in 1968, so they remained until Amtrak. Penn Central had more serious matters to worry about than train names, so they were not about to rename the New York Central trains after the merger.
I had left the New York Central before the merger, to work for the Delaware and Hudson (which retained the names of The Laurentian and The Montreal Limited) so I never had the pleasure of testing the Penn Central passenger service west of Buffalo. I did hear, though, that the operation often became very interesting, to say the least, especially in the winter.