I tested the online 'build' feature here in Canada using my own address, then did it again using a Montana address.
The "Max Payload' or 'HD Payload' feature was NOT automatically included when the Max Tow package was selected on either of the builds. In Canada, the total payload capacity did change when the Max Tow package was selected, and it changed again when I selected the 3.73 locking rear diff as well, which I suppose should be expected.
The other detail that became apparent when I ordered was that the features and options packages also differed between my online build using the Canadian Ford website and when we were sitting at the Order desk at my local Ford Dealer.
All I can say for sure is that you need to be VERY careful if you build your own truck at the dealership. Have a list handy and check every detail several times over before submitting the order. It took me quite a while to exactly match my selections from the Canadian website to the dealer online system.
Assume nothing, check everything!
Dave & Jill
2012 Ford F-150 EcoBoost
2012 Surveyor SV-294
2 kids, one dog (a Golden)
Let's go camping!