The engine is a LS3 376/525 with AMA cam shaft. Has a very aggressive throaty lob at idle. Sounds great while accelerating. Drives very smooth on the interstate at 75 with minimal noise in the interior due to the 6 speed. Terrible mpg so far but not the point. Tophat is going to add an accessory fuel 12 gallon fuel fuel tank so I can have decent range. Love it so far. My Tesla is feeling lonely.