Ardun heads. 200 sets made to boost power on Ford V8s to 300 hp on gas, 500 on nitro. Don Garlits owns 4 sets, here is the best, burning nitro

Skip the 1st 25 seconds

Found on http://www.enginelabs.com/news/video-big-daddy-don-garlits-fires-up-ardun-headed-ford-on-nitro/