I am in the midst of putting a 9" in my '61, from an 80's F150.
Overall width of mine is 65" wide, which (so far) is working great with 18" Jeep Grand Cherokee wheels (6" backspacing). I did order new axles with 5x5 bolt pattern on them to match my Frankenstein squarebody/OBS front suspension.
The new axles are "cut-to-fit", which might be a good way to go: if you shorten the driver's side axle tube, you could then shorten the axle shaft, and thus re-center the pinion and match the width of your original axle.
The existing pinion offset might become an issue with fitting the driveshaft through the X on my '61, but your '63 doesn't have an X, correct? I don't have a driveshaft for it yet. The low-mounted pinion is good for driveline angle on a lowered truck.
I made my own saddles, but Captain Fab makes them too.
