Z-11 427 Impala
» The Details
» The History
The R.P.O. Z-11 optioned Impala was designed for one reason and one reason only... Racing. Cubic inches were climbing fast in '63 and the Z-11 427 Impala was Chevrolet's way of keeping up with Ford, Pontiac, and Chrysler at the track.
The 427 was a modified 409 engine. The stroke was increased, special heads, valves and intake manifold were added. Fuel was supplied by 2-4bbl Carter AFB carburetors. A special cowl induction air cleaner was also used.
This car was all performance and no frills. You wouldn't find a radio or even a front sway bar. Most Z-11's were ordered with the heater delete option and no sound deadner. Light and fast was the idea with this car and to help lighten it, the Z-11 came with an aluminum front nose and other parts. Hood, fenders, front and rear bumper, front and rear bumper brackets and braces, grill brackets, a 2 piece riveted fan shroud, grill filler panel and hood support catch were all made from light weight aluminum making the car about 300 pounds lighter than a similar 409 powered production car.
To stop the car, sintered metallic brakes and special venting screens and air scoops in the backing plates for added cooling were used. All Z-11's came with T-10 4 speeds, a beefed up posi rear and a 4.11:1 gear ratio. (code JA)
Only 57 Z-11 optioned Impala's were produced and only 7 are thought to be in existance today, making them an extremely rare and valuable piece of Chevrolet history.
Although the Z-11 was made for racing, they weren't directly sold to race car drivers. Some ended up on car lots. And although 1963 was the only year for the Z-11, there were about 20 C.O.P.O. 1962 Impala's built mid to late in the year with aluminum front ends and equipped with 409's. These 409's had special features like the Z-11 intake manifold, special camshaft, heads, etc. There were also 18 extra sets of aluminum front ends made for that year and sold to race car drivers.
The base price of a 1963 Impala was $2774.00. Adding the price of the R.P.O. Z-11 option of $1240.00 to that brings the total price just over $4000.00 not including destination charges, taxes, etc.