Actually, it should be possible to swap the 10" brakes in place of the 9" parts because it was available that way from the factory, at least on the Ranger variant it was (Payload Package 2).

You'd need more than just the drums and shoes though. The backing plates are also different between the 9" and 10" brakes and at least some of the self adjuster and spring hardware probably is too. On many years, the slave cylinders are both the same 0.75" ID although that doesn't necessarily mean that they are the same part. With a little research, a swap between 9" and 10" should be easy.

But that brings up another point. Have you actually verified that yours are 9"? If nothing else, you can measure the outside diameter of the drums.

9” drum – roughly 10.5” OD
10” drum – roughly 11.75” OD

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2003 FX4 Level II, Supercharged 5.0L V8, Headers, Duals
BW4406 manual transfer case, Aussie Locker, Torsen L/S, 4.10's
Bilstein 7100 rezzies, Cadillac/Mustang rear discs, Duff traction bars
Keypad Entry, Lock LEDs, ABS switch, sway bar discos
Heated seats, Explorer EATC, Trip Computer and consoles

2003 XLT 2.3L M5OD-R1 reg cab, 2011 Taurus SEL, 2016 C-MAX Energi Plug-in Hybrid