I'm about to start a project, (DIY Kayak rack) - and in planning - I started taking measurements of the bed of my '01 Silverado 1500.

The front stake rail holes (inside to inside) measure at 65" between them.
The rear stake rails measure at 63-1/16" between them. Almost 2" different! Is this normal? I Thought maybe things got tweaked out of square when my daughter hit a pole in a parking garage (passenger side door and bed body) when making a tight turn a few years back - but I've not noticed any dog-legging of the rear end - and I measured the diagonal distance between the stake rail holes - both were EXACTLY 93" between for the diagonals.... so apparently it's square.... but how can a distance of 2" difference be accounted for between front and rear stake holder holes? Is this just the way they are?

The tailgate opens and closes perfectly... Ideas?