The Z16 SS396 Chevelle

Chevelle. Specifically, the big-block Chevelle. Arguably, the most dominant car of the muscle car era, not only for their brute force and power on the streets and strips, but the sheer volumes of them produced. But many folks aren’t aware of the story behind the beginning of the big block engines put in the Chevelles, and initially, why.

To understand Chevy’s move to add big block power to their new intermediate size car in 1965, you need to jump back a year to 1964, and scoot over to Pontiac…..

In 1964, Pontiac General Manager, John DeLorean, realized the 326ci small block engine offered in the new Pontiac Tempest (327ci in the Chevelle) was never going to satisfy the “need for speed” of the younger generation of the day. While the 326 was a great little engine, the “kids” were building their own power plants and putting them in anything they could get their hands on, to go street racing. Being the visionary he was, DeLorean thought that if we give these young people a reason to buy a Pontiac now, they’ll be more likely to come back and buy more Pontiacs later. So he had an idea that he took to the GM Corporate guys for approval.

His idea was a special option package for the Tempest that would include the Pontiac 389ci big block engine with a tri-power carb setup, a 4-spd transmission (with a Hurst shifter – because the kids had to have a Hurst shifter!) heavy duty chassis, suspension and brakes, bucket seats, and various rear end gear ratios. All this go-fast equipment would be put together as an “option package” for the Tempest. All they needed to do was go to their local dealer, order a new Tempest and check the option package box for the: GTO package.

Originally, the GM Corporate guys were skeptical, but they also liked Mr. DeLorean and gave him approval to build 3000 of the cars. As the story goes, they never expected it to fly with the public, but knew John was a brilliant marketer so decided to appease him ….

As the 3000 car build was coming to an end – and they were selling as fast as they could build them! – the story is that the Pontiac dealer network across the country went crazy because people were begging to buy these cars! The Corporate guys took note and realized DeLorean might be on to something, so they let the cars continue to be ordered and built. Well, 32,450, 1964 Pontiac Tempests with the GTO option package later, Pontiac had an enormous success, and John DeLorean is still credited with beginning the muscle car era.

Over at Chevrolet, they were busy putting the first big block engine in the Corvette. The 1965 model year was under way and the car was introduced a bit late, but nonetheless, the big block, L79, solid lifter, 396 / 425hp engine came to market. But Chevy General Manager Semon “Bunkie” Knudson had another issue to deal with.

The success of the GTO at Pontiac was leaving the Chevelle in the dust in sales in the intermediate car segment. By 1965, Pontiac decided to make the GTO a stand-alone model, also changing the name of the Tempest to the Pontiac Le Mons.

Knudson had his own idea to spark some competitive sales of the Chevelle against the GTO. His idea was a group of promotional cars – 200 to be exact – with his own “option package” called Z16.

The Chevelle Z16 would include the L37 version 396ci big block with hydraulic lifters and 375hp. This would be 15 more horse power than the 360 in the 389 Pontiac GTO. The 200 cars would be built on the frames intended for Chevelle convertibles as they were boxed and stronger. They would have Muncie wide-ratio 4 speed transmissions, heavy duty suspensions and chassis. Brakes needed to be sourced from the Impala parts bin as the 396 engines were already in use in the full-size cars, but stock Chevelle brakes were not up to the 375hp task. The 11 inch drum brakes used on the Impalas would work fine though.

Chevy used 6-inch wide wheels instead of the standard 5-inch units on production Chevelles. They had Firestone develop “gold line” tires for the 200 cars. Special wheel covers were designed for the cars too. Emblem placement was different on the outside of the Z16’s as well as trunk lid trim which was only the lower half of the rear deck lid and it was painted black. Production cars had chrome and polished aluminum on the trunks. Even the tail-lights were different and sourced from the 300 Series Malibu.

Inside, special bucket seats were added and a padded dash with what looked like a dash mounted tach fixed in the center. It was actually a clock and the tach was large and next to the speedo in the dash cluster.

They chose only 3 colors for these promotional cars – Regal Red, Light Crocus Yellow and Black. There were a couple interior colors used, red, black and white and some cars had vinyl roofs installed.

It was too late in the 1965 model year to introduce a new Chevelle, but the car was slated for a complete new body style change in 1966. Knudson’s idea was to sell these cars to prominent people who were in a position to promote Chevrolet and all the new big block power options that were available in the Chevelle. They were never advertised and other than the celebrities who the Z16’s were offered to, only a select few “regular folks” were able to buy one. The most famous Z16 owner and person who probably talked about his car the most was Dan Blocker, who played “Hoss” on the Bonanza TV series. Dan was a huge performance car fan and  bought his Z16 at Nickey Chevrolet in Chicago. The fact that Chevrolet was one of the only sponsors Bonanza had didn’t hurt is ability to promote the car for Chevy. Other notable owners were AJ Foyt, Phil Hill and Briggs Cunningham.

There was a 201st car built and it was a convertible that Bunkie Knudson had assembled for himself. All the other cars were identically equipped hard-tops except for color and trims. The Knudson convertible is known to have been destroyed many years ago, but a clone or two have been reportedly built. Of the 200 promotional cars that went to mostly celebrities, there are various estimates of genuine originals that still exist. Numbers range from 65 to 74, depending on the source.

The Z16 SS396 Chevelles were heavily optioned cars – and by Chevelle standards of the day, expensive. A Z16 Chevelle would have cost nearly $4300. Back then, that was nearing Corvette money compared to the average Chevelle cost of $2800 to $3200. But the intent was never to sell the Z16 as a volume car. They were meant to introduce the lineup of Chevy big block power to the world as a stepping-stone to 1966 and beyond.

These numbers matching, documented examples have been owned by Rick Treworgy for many years and are on display at Rick Treworgy’s Muscle Car City Museum in Punta Gorda, FL.    

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