Driveshaft length

Need some info on the length of the driveshaft for my 67 Dart. Currently it has
a 360 bolted in with the Schumacher kit, 727 auto and an 8 3/4" rear end.
Originally it was a slant 6, 904 and 7 1/4" combo.

The Dodge factory service manual says 52 and some odd inches, but I don't
think I'm measuring correctly. I get 49 3/4" from center to center of the
ujoint caps and I'm about a half inch long. That is with the yoke all the way into the trans.

Thanks for any help.

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