I've got a 904 and 727 side by side and the 727 is longer. I think the 727 was out of a B-body.
Looked in the Mopar Chassis manual 8th edition, pg.48 figure 4-1. It says 727 is 34.39 inches long from front to tail housing end. The 904 is 30.50 inches. it also says SPECIAL NOTE There is a...