Hello Tango:
Interesting! I noticed from your signature line that you're in an extended cab while I'm in a double cab. That could account for the difference also. The take home message is that everyone ought to take measurements of their own set up to make sure they get the best results!
Attached is a photo of the measurements I used for our truck (atcually our 1st truck that was totalled by a drunk driver).
Howard
Howard, just to check, are you running 255s in this photo? Or 285s?