You have 10". The smaller brakes were on the 2wd or 2.3 trucks. Pic 2 is the correct measurement.

 

yup - also if you clean up the rusty crust around the outside of the drum on the "face" rim contact side the stamped writing says the max diameter the drums can be before they need to be replaced. It will say something like 10.285" or something thus 10" drums. your 2nd to last pic shows the writing near the wheel weight looking thing. They can get so rusty they cant be read but yes drums are measured from inside to inside braking area, rotors are outer edge to outer edge for diameter.

FYI the edge version has 10" brakes on 2wd.

 

 

Good visual reference here: https://www.ranger-forums.com/drivet...m-size-135609/

They look quite different