'65 8-3/4 and 904 Trans, Driveshaft Length?

From my 69 FSM it says for a Dart (same 11 in WB as the 65), the length of the driveshaft should be 52.27 in from C/L to C/L of the U joints. This is for an LA motor with 904 and 8.75 axle. Just for info, if with a 4 speed and 8.75 it is 51.96. All driveshafts are 3 in in diameter and some have the IVA (Internal Vibration Absorber at the front u joint.

EDIT: BTW will be doing the same set up in my 65 'vert - 340/904/8.75