I think your out of luck on this one...of course Ford is making the aluminum version of the old Cobra Jet heads but they're over $2,000 a set and are not for low RPM usage. Your best bet would be to find a set of "Police Intercepter" heads that were put out a few years around 1972 through 1974. They had the large valves of the Cobra-Jets but had the small ports for more torque. Depending on what year your truck is a stock head can make at least 450-500 HP with the right cam, intake, carb, headers, etc. A set of Cobra-Jets will bump you up to 600-625 HP max and a set of "TFS" heads will give an easy 725 HP...but again that's not for street use! If you have a 1989 or later truck you need to find an earlier set of heads. Mid 1989 Ford reduced the exhaust port size and in the early 90's Ford made them smaller still. Those smaller exhaust ports just "chokes the life" out of the newer engines. Give us more info on exactly what the truck is used for and what you currently have (type of tranny, gear ratio, tire size, year, carb or injected, etc.). Deen