Hi Red Hawk:
I'm new to all this and unfortunately can't say I have a firm understanding, but happy to share my experience. (Started on P.33 of this thread)
On October 2, 2023 I met with my small but reputable GMC dealer. I had already configured (built) the truck I wanted on GMC's website and was able to present a printout of the options / packages that I wanted. The dealer used that information to generate a "Deal Sheet" that listed the trucks configuration and the agreed price. It appears the "deal sheet" was generated internal to the dealer and was representative of the Window Sticker would be. I was required to check and initial each line item (option/package) on the deal sheet for accuracy, great idea in my mind. The deal sheet listed a specifically assigned "Deal #" & "Customer #". At that time I was informed clearly the dealer had no idea when my truck would be built. Fast forward .....
December 14th 2023 I got a call from my salesperson stating the factory had "picked up my order" (allocation assigned), however the 5th wheel / ball mount package was constrained, I hung up and drove to the dealer. While at the dealership the salesperson made a call to his GMC factory rep and told me he resolved the constraint. Also, I was told I could add a small option. The salesman presented me with a revised configuration that was generated on the corporate GM order Workbench system. The workbench order listed my newly assigned order number and "allocation group". I was once again required to check and initial each option/package line item for accuracy, again, good idea.
At that time no firm delivery date could be established, however a welcomed "wild ass guess" of about early March was offered. That estimate seems consistent with the what I am reading on this thread that it takes about 8-9 weeks after the factory picks up the order. Simply out of excitement I will likely reach out to my salesman for an update.
I hope this verbose response may offer some assistance, and maybe someone will chime in with additional information.