No cars in the video are spraying. I know the silver SS has a rebuilt motor, but from what I know, it was rebuilt to stock spec, from compression to displacement, just with a better bottom end for future power. JWall (SS) wins many races because of his driving. He can row!
For the SL65, I believe he uses an OBD flasher, adds boost, adds fuel, adds some timing, and changes the shifting strategy for the transmission. It takes it to 670/740. It also cost ~$6500.
Thats not bad at all! Thanks for the info!