You first said: So, yeah, an original Cobra, even a Dragon Snake would not likely run those numbers with original heads. But with modern heads, I don't think it would be a problem, even in a leaf spring car. I am pretty sure that you could get an original 289 car into the high tens/low elevens with a built 289. It's just that most guys don't want to risk their bit of history to prove it. There were some 427 cars that went drag racing and got some decent numbers. I will look them up for you. Edit: From a historian at the Shelby Registry... "CSX3198, the Harr Ford 427 ran in A/Sports with a best time of 10.38 seconds @ 138 mph and, using hi-rise tunnel port heads, in A/Sports/Modified with a best time of 10.02 @ 146 mph. In 1966. the car helds both ends of the National Record, E.T. 10.86 seconds, 127 mph (A/SP, NHRA), ’66 Winternationals, (Pomona), ’66 Summer Nationals (Indy)." Info courtesy of the Shelby American Automobile Club (SAAC) World Registry of Cobras."
Well. You can tell the the MPH is based on weight not HP. Even with the tunnel port heads and high rise, which today are not the best for CFM in cylinder heads, the ET is still for an extensivley modified car. A 289 car with steel 187 heads will be hard pressed to make 440hp and it will be pretty lumpy. Oh, I worked on a Dragon Snake with Peter Klute at Legendary Motor Car. I completed the final tune on the webers and also did drive it a few times. I also spent some time with Ken Dondero ( Don Nicolson) Cammer Maverick in the early 70's, pro stock 9.57/9.52 You can make a lot of these old cars fast with today's cylinder head tech, but that was the 60's.