1963 Cadillac Series 6400 Eldorado Biarritz

One of the most glamorous Cadillacs from the 1960s

The iconic Cadillac tail fin was tapered again 

Cadillac for 1963 had surpassed its own great reputation. It had been completely redesigned from the ground up. In luxury, performance, and craftsmanship, the 1963 Cadillac Eldorado Biarritz convertible did just that- Cadillac built upon its heritage; its engineers refined the brilliant styling, comfort and convenience features into the elegance of the all-new Eldorado Biarritz convertible for 1963. If one word could aptly describe this limited production car, it would be ‘splendor’.

With its excellence of design, dedication to assembly in the finest manner, and its universal acceptance, one was always confidant knowing that no more luxurious form of motoring existed….they were already “there.” The Eldorado Biarritz was the most glamorous of all 1963 Cadillac models.

This all-new design was every inch a Cadillac. The iconic Cadillac tail fin was tapered down again and soon to disappear forever. A Cadillac’s styling was evolutionary. The overall styling for the 1963 Eldorado Biarritz was crisp and sculptured. The entire car was lowered creating a lower center of gravity most important to a convertible’s integrity. Even with its redesign, the 1963 Cadillac retained its cult following. The 1963 Eldorado Biarritz possessed that poised dignity that was the hallmark of every Cadillac.

From its authoritative front end design to the sweep of its tail fins; this fresh new interpretation of definitive Cadillac luxury surpassed the famous cars they superseded. Under the hood was a greatly refined engine lighter in weight, quieter and smoother in operation than ever before. Luxury was one’s constant companion with the elite Eldorado series. The Eldorado Biarritz convertible offered a new spirit of vitality and youth.

The 1963 Cadillac Eldorado Biarritz convertible was one of motordom’s most glamorous cars. The dramatic styling of the 1963 Cadillac was no more majestic than with the Eldorado Biarritz. This spacious and elegant convertible with its aristocratic air had the look of unique individuality.

A leather upholstered interior by Fleetwood, a fully automatic power folding fabric roof, power windows, and power seats were just a few of the myriad Eldorado Biarritz standard features. No other fine motor car provided such convenience, luxury, and distinction than the “Standard of the World.”

A major innovation for the 1963 model year was the new true-center drive line. This advanced design and precision assembly of the unit isolated and cancelled vibrations and driving impulses. The flow of power generated from engine to rear drive wheels was smooth and direct under all driving conditions. Cadillac was constantly refining the magic carpet ride.

The newly re-designed engine was shorter and narrower than the previous 390 CID V8 engine. The bore and stroke remained the same at 4.000 X 3.875, all components except valves, rocker arms, cylinder heads, and connecting rods were new. Its crankshaft was made from GM’s patented “ArmaSteel” which was lighter in weight and stiffer. With all of its refinement, the new 390 CID was more rugged and efficient. The re-designed Cadillac 390 CID 16-valve OHV V8 engine weighed only 600 pounds, it was 100 pounds lighter than the Rolls Royce alloy engine and its displacement was smaller than the Cadillac’s.

The engine used a Rochester 4-bbl down-draft quadrajet carburetor with equalized manifolding, mechanical fuel pump, polyurethane air filter, and an automatic choke. This engine was mated to GM’s Hydra-Matic (Jetaway) 4-speed automatic transmission that was the fully automatic step-gear type with controlled fluid coupling on forward gear set for smooth shifting. This new redesigned 390 CID produced 325 hp @ 4,800 rpm with 583 Nm of peak torque @ 3,000 rpm. Performance was rated as 0-60 mph in 10.4 seconds, 0-100 mph in 28.7 seconds, and had a top speed of 125 mph. It could do the ¼ mile @ 84 mph in 17.6 seconds.

 As a safety measure, these precision engines were assembled in an air-conditioned environment to maintain a constant temperature to provide maximum precision in measurements. Per Cadillac, “The secret is superior manufacture and assembly is a well-engineered engine that’s built right.”

That was the legendary Cadillac tradition of production standards that made Cadillac the “Standard of the World” in design and technology. The Cadillac key to success was maintaining the standard: dedicated personnel at every level to provide an outstanding automobile every year. 

The 1963 Eldorado Biarritz was built as body on frame construction. It rode on Cadillac’s rugged tubular-center X-frame which permitted a lower interior front floor increasing seat height and headroom. It had the luxury length of 223’, and rode on a long 129.5” wheelbase, with a width of 79.7”. The front suspension used spherical joints with independent helical coil springs, new rubber mounted strut rods and rubber bushings to absorb impacts and isolate road noise.

The rear suspension utilized a four-link drive, helical coil springs, and rubber bushings for a quieter and softer ride. The hypoid type rear axle had an offset differential housing to provide straight line drive. The optional controlled differential directed power to the rear wheel having the best traction. Hydraulic power brakes with self-adjusting shoes, finned front and rear drums, and dual hydraulic master cylinder were standard features. Also standard was power steering with fast response and short turning diameter. Eldorados always came standard with five whitewall tires. 

An eloquent expression of glamour was the dramatic 1963 Cadillac Eldorado Biarritz convertible. The comfort and luxury found in this spirited automobile were crafted in the finest Cadillac tradition. Under its hood was the greatly refined Cadillac 325 hp V8 engine that was lighter, quieter, and smoother in operation. The Eldorado Biarritz provided a full measure of Cadillac luxury and power amenities.

Luxury and elegance with a sporting attitude made the 1963 Eldorado Biarritz a unique and distinctively different kind of automobile. Cadillac had been universally recognized as the “Standard of the World.” This enviable position was garnered with ingenuity, skill, and dedicated engineering. Once again the Cadillac emblem adorned one of the most impressive motor cars in the world…..will they ever again offer the “Cadillac of Cadillacs?”

1963 Cadillac Series 6400 Eldorado Biarritz convertible, only 1,825 built