09 Express 4L85e to Allison

Forgive me if I am in the wrong section.
I am wanting to swap a 4L85e for a Allison 1000.
My express is an 09 model LMM.
I can manage the wiring changes, but as far as programming goes would I need to switch the van to a truck OS and is it compatible to switch these OS's?
Which TCM would I need, T42A?
Any insight or a brief run down before I go all in from someone more experienced on these. I do tons of gas conversions, but the diesel compatibility is all new to me. Can anyone give me some recommendations or anything you think I would run into doing this swap. Thank you

Hi, you want to have a pickup powertrain in the van, so I guess the wiring , tcm, ecm cal. should be the same as a pickup
I always thought that the Allison can't fit on a van because the floor pan doesn't allow enough space ?