From what I have been able to find out, the factory is not set up in such a way that they can handle the added length of the longer megacab with an 8 footer. The cost to retool the factory to sell a few trucks (in comparison to the volumes that are sold in the shorter versions) is not enough to justify until the next major redesign in 2009 or so. Until then, the sales numbers don't justify interupting the current production line to rearrange it to handle the longer frames for only 1 or 2 more model years. DCX knows they will sell, but they also know what it will cost them to make them.