On the Utube comments, Cameron says its a 6.2 with aluminum heads... I would think it's a Hemi. Hang onto your seat when you watch this Vid of the Lime Rock T/A race. Look like the LS camaro of Andretti pulls him, but the outcome is what matters. Hemi gets it done! These TA2 cars are limited to under 500 HP.. https://www.youtube.com/watch?v=6sX0vNIJHnU