I know the New Haven revived these special race trains after WWII and they continiued through the Dumaine and McGinnis years. At the time they used convenitonal equipment, a mixture of postwar 8600’s and prewar 8200’s (“American Flyers”), leavng from the New London station, corssing the high-level bridge to Groton, and going up the Themes River line in the direction of Worcester. MIT competed in these races. The bankrupcy and subsequent merger into PC ended them. But there has been talk of revival under Amtrak and Providence and Worcester. For all I know it may have happened.
The Lehigh Valley ran similar trains along the east shore of Cayuga Lake in Ithaca, NY for Cornell U. races.