There is some show on the travel channel right now (6pm edt).
I noticed the majority of the trucks so far have detroits in them. One had dual cummins.
Also, several have alison autos.

What are your thought on the combination of Detroits and Alisons for high performance hot-rod toy semi's?

 

An automatic is quicker, no doubt about it. And when you want to do burnouts and donuts, it's way easier to put on a good show. The Detroits are popular because of the huge power that can be packed in a (relatively) small package due to the 2 stroke design. Fuel economy, longevity, and oil consumption are all non-issues.