904/727 swap

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 short extension for the A727 used in certain truck models. Are you lucky enough to get the short one and it be the same as 904? I hope it's like fastbackcuda says, that would be great. good luck. Ray