I have the Gt40 Heads off of the Cobra... I didn't look that close, I didn't know they were the alumminum heads. Yes according to the dyno sheet the car is making around 270 hp and he did have good traction.. but I did beat him threw first and was right with him in 2nd. I did do this on the street at 2:00 the morning after work, but it was far away from any residents and we jumped on the brakes right after.