Just trying to do the math...let's say it has a 48" bed length and 40" bed width. That gives it 62" from the front corner to the rear corner diagonally (5' 2" long). Just guessing, but if the tailgate is 16" high, that would change the bed length to 64" with an extender, making the diagonal corner-to-corner length 75" (6' 4" long).
I often think about bed length in terms of front-left corner to rear right corner, because that's how I load lumber if I'm getting a few boards for a project. Obviously that doesn't work for a contractor who's hauling a lot of lumber, but they wouldn't be buying this truck anyway.
If my numbers are correct above, the bed would be okay for bringing home 8' boards safely without an extender, but a tailgate bed extender would allow for 10' boards pretty easily. I think a bit of strapping would be prudent in either case.
If we're really going into the math, let's use some of these pics to find bed length x width x height ratios
Also now that we have spy pics with tire sizes, anyone with photoshop skills able to pull off a guess at overall length?