The 1963 Z-11 427 Impala

[Dog427435]

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.
Z-11 Facts and part numbers:
Produced only in 1963
The R.P.O. Z-11 option was an additional $1240.00
Shipping weight-3245 lbs.
Curb weight-3405 lbs.
57 Z-11 Impala's were produced
Only 7 are known to be in existance today
Modified 409 engine rated at 430hp@6000 RPM's. (Actual
horsepower was 480-525)
Block casting #3830814. Code "QM"
Block part number #3838253
Cylinder Heads #3837731 2.19 intake/1.72 exhaust
Valve Covers #3837739 (left), #3837740 (right)
Oil pan (deep sump) #3816322
2 piece Intake manifold #3830623 (top)-#3837733 (bottom)
Waterpump #3837691 (aluminum)
Cam #3837736 .556 intake/.556 exhaust lift with 325 duration
Crankshaft #3837472
Distributor #1111023
Coil #1115107
Generator #1100628
Starter #1107274
3.65" piston stroke
4.3125" bore (same as 409)
13.5:1 compression ratio
Special cowl induction air cleaner #6418986, #3839764 (duct)
Tach (redlined at 6200 rpm's)
Borg Warner T-10 4 speed transmission (close ratio)
Special posi rear with 4.11:1 rear gear ratio
Sintered metallic brake shoes
Screened rear brake backing plates with air scoops
15 X 5.5 wheels with 6.70 X 15 bias ply tires
Front coil springs #3824693
Rear coil springs #3824694
Deleted front sway bar
Optional sound proofing and insulation delete on most
Optional heater delete on most
Hood #3837710 (aluminum)
Hood catch #3837718 (aluminum)
Grill filler panel #3837750 (aluminum)
Left fender #3837765 (aluminum)
Right fender #3837766 (aluminum)
Front bumper center #3837751 (aluminum)
Front bumper LH #3837755 (aluminum)
Front bumper RH #3837756 (aluminum)
Rear bumper center #3837752 (aluminum)
Rear bumper LH #3837753 (aluminum)
Rear bumper RH #3837754 (aluminum)
Front bumper bracket LH #3837763 (aluminum)
Front bumper bracket RH #3837764 (aluminum)
Rear bumper bracket LH #3837757 (aluminum)
Rear bumper bracket RH #3837758 (aluminum)
Rear frame to bumper brace LH #3837759 (aluminum)
Rear frame to bumper brace RH #3837760 (aluminum)
Thanks to http://www.348-409.com/ for all the above info

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[b]Finding one of these 7 beauties is tough - but going to a show and seeing 2 side by side is amazing!!
One completely stock and the other in race trim!!

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[1969l78]

Very nice

[Tarrytown SS427s]

Those are awesome cars. I saw them at the GM nationals several years ago with the Old Reliable, and than saw the Old Reliable by itself last May at Musclepalooza. I think the owner is Don Fezell. My father has Z-11 waterpump..I wish he had the rest of the car!
Steve

[tom406]

I know it has a terrific caretaker, but that Alan Green car really needs to come "home" to Seattle. Maybe I should start putting my nickels in a jar.....

[ANDY M]

and a whole lotta dimes.
Watching the "Sox Sinclair Service" Z-11 staging at the SCR last year beat all of the cars I've seen with velvet ropes around them.
https://www.yenko.net/ubbthreads/show...0/fpart/6/vc/1

[markjohnson]

In my opinion, Chevrolet's maximum drag racing effort was the 1963 Z-11 Impala. A close second would have to be the 1969 ZL-1 Camaro. Everything else was street cars. The number of special components on a real Z-11 is unbelievable. Can you even imagine what would have been produced in '64-65 if the GM ban on racing did not go into effect in mid 1963?

[Belair62]

By far the most significant dedicated drag racing RPO ever built by Chevrolet. Would have been really cool to see the one at SCR driven hard. Can't say I blame him...breakage is not a real good thing with something like that...