Just pressurize the current srt and be done with it. Chevy did it with the zr1 - ford with the gt500 and shelby's. Now its dodge's turn
They put the engine in everything else, doesn't seem far fetched to me. Out of the Mustang,Camaro,Charger,and Challenger the Challenger is still by far the best looking on the outside IMO. Last time I drove one the interior was pretty boring though and other than being a sweet cruiser I think it's too heavy for anything performance-wise.
Who cares what kind of mileage it would get. Its an awesome concept and would destroy the Camaro. The body style is great to begin with, its just that they are slug slow, especially compared to the newest Mustang. With that engine that would all change.