True Connections

Here we are in 2006, which brings us to the 40th anniversary of the 1966 Chevelle and El Camino. In 1966, Chevrolet produced a total of 471,052 Chevelles and El Caminos. It was an exciting time for prospective Chevelle owners since this is the first year that the Big Block Chevrolet engine was a readily available option in a Chevelle or El Camino. The Big Block 396 was offered in three horsepower ratings, the 325hp was standard with the SS package while the 360hp engine was an extra cost option. The third and little known option was a 375hp engine which we will discuss more about in the next issue. Perhaps the rarest option in 1966 was the cowl plenum air cleaner, which would have been purchased through Chevrolet. In the 60s, Chevrolet had developed close relationships with many top names in Nascar, one of which was Smokey Yunick. Smokey had designed an air cleaner that was totally enclosed except for duct work that channeled cold air from the cowl into the carburetor. In order to utilize the design Chevrolet had to have a number of them produced for use on various models. One design was meant for use on Chevelles and full size Chevrolets, and a different design was used for Camaros in 1967.

These air cleaners are now reproduced and can be found for under $2000. Some may cough and gasp at that price, but should you be one of the handful of people to own an original, you can demand around 3 times that price. To install your shiny new cowl plenum air cleaner is relatively simple. You have to start out with a non air car since the ducts mount up to the firewall where the air conditioning boxes mount. To begin, simply mount the air cleaner assembly with the duct, onto the carburetor. Align the opening of the duct so it touches the firewall, then trace around the duct with a scribe or pen and use a transfer punch to mark the 6 mounting holes. Remove the duct and draw a new line ¼ inch inside your original outline. This is the hole you need to cut out. We use a hole saw on each corner to make nice round edges, then cut the rest of the sheet metal out with a pneumatic body saw. It’s always a good idea to cleanup the edges with a file so no one gets cut and then drill out the mounting holes. Next, apply a length of strip-caulk or other type of weather-strip material to the flange of the duct. Reinstall the duct to the air cleaner, and install the six screws that mount the duct to the opening in the firewall. The performance gains of cold air intake will be obvious, plus it looks cool, but unfortunately the price tag makes this option not for the faint of heart. Next month we dive into some more 1966 special high performance options.