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