The main focus of this article is how to install Hedman Elite headers and induction on big-block Fords that need to remain smog-legal plus gain a little horsepower and fuel mileage in the process. In addition I'd like to inspire CLASSIC TRUCKS readers to look into non-exempt trucks. This is an untapped source of slightly later-model classic trucks that can be had for considerably less money. Beyond California's borders there are numerous states that enforce vehicle emission laws. To learn the smog requirements for your state please visit www.semasan.com.
Getting back to my 1976, fortunately the factory smog equipment on the truck has never been tampered with, and because the GVW (gross vehicle weight) is over 6,000 pounds it wasn't originally required to have a catalytic converter. In 1975 all cars were required to run a catalytic converter, but trucks over 6,000 GVW weren't until 1979 (1978 in California).
Preparing a 360-inch Ford engine with some miles on it to pass smog can be a hassle, so we're going to install a pair of Flowmaster catalytic converters to hedge the bet. In the mid-1970s, factory-installed catalytic converters were heavy, extremely restrictive, and parasitic loss was substantial. The new Flowmaster cats are one-quarter the size, much lighter, and flow as efficiently as high-performance mufflers. In this month's edition we'll cover installing a set of smog-legal Hedman headers, and pay special attention to any repairs that should be handled while things are easier to access. In next month's issue we'll hang the exhaust system from the cats back, freshen up the cooling system for summer, and then go pass a smog test.