it was actually just a guess but it makes a lot of sense. ive never had a std cab but ive had 4 ext cabs.
S-10 \ S-15, Rangers and I am pretty sure Nissans.....bed length is the same, Mazda seems to almost be the "different" one out there...not that I am complaining but it does make life easier when looking for a bed if yours happens to be trashed
actually on nissans if i remember right the ex. cab is about an inch longer or it could be the other way around
the beds are not shorter the length of the boxes are the same what is different is the position of the wheel wells. this has been brought up before and I have both style of boxes in my garage and they are the same lenght and width just as I wrote the wheel wells are in different spots. The only other differents between boxes is if you have a 4x4 box as the wheel wells have a larger opening and are flared.