The venerable engine that traced its roots to 1949 generated 345 hp (350 PS) and 435 lb-ft (590 Nm) in its triple two-barrel carburetor setup. The mainstream single four-barrel carb installed on the same 6.4-liter motor was good for 325 horses and 430 lb-ft (330 PS, 583 Nm).

A four-speed Hydra Matic transmission sat behind the engine, irrespective of its output, but the rear gearing was model- and option-specific. The low- and mid-range Caddies came with a 2.94 standard differential, and the option was a 3.21 (available at extra cost).

Photo: YouTube/Lou Costabile

For the Eldorado, the standard equipment was the 3.21 axle, with a 2.94 optional (the exact opposite of the rest of the lineup). However, when the buyer opted for the power-robbing air conditioning, the rear diff could only be a 3.21 ratio. The biggest of them all, the Series 75s, rode on a 3.36 differential as standard, with the option to replace it with a 3.77 (the gargantuan barges neede all the extra help to get going).

It goes without saying that whoever ordered a Cadillac didn’t consider a few dollars more for creature comforts, and I’m not talking about luxurious upholstery or fancy materials. Cadillac prized (and priced) technology very highly. Air conditioning alone was around $500, and a radio with a speaker in the rear bench added another $165.

Power windows, six-way power seats, and power vent windows cost a hefty $270, and the remote-control trunk lock upped the ante with an extra $60. Cadillac offered automatic headlamp dimmers (50 bucks), and electric door locks and even air suspension. The last two options totaled $260 but were provided as standard on the Eldorado.

Photo: YouTube/Lou Costabile

A well-equipped Cadillac could be well over $1,000 above the base price. However, most of the costly equipment was included when a high trim was ordered. That’s the case of this stunning 1960 survivor Cadillac Eldorado Biarritz, owned by the same man since 1975. Half a century of single ownership says something about a car guy, but fifty years of Cadillac ownership is top-tier piston addiction.

John McConnaughay from Geneva, Kane County, Illinois, is that man—he’s the one driving the special drop-top in the video below. His champagne-over-red leather interior Caddy has 40,974 miles on the clock (65,941 kilometers), and he drives it regularly—albeit for short cruises. Still, the car is no garage queen.

The Biarritz was Cadillac parlance for ragtop Eldorado – one of the rarest among the division’s 1960 production volume but the most numerous within its series. The other two, the Brougham and the Seville, accounted for less than half that year’s total Cadillac Eldorado automobiles.

Photo: YouTube/Lou Costabile

The featured vehicle has all the conveniences available for the model year, and the long-time owner is very proud to state that the only things he changed during the 49 years of custody are the airbags for the suspension system. The rubber bellows aged poorly and was expensive to repair, and Cadillac denounced the floaty setup for the following year. But when the air springs worked correctly, the ride was jet-smooth.

Even the dual-exhaust system maintained a composed attitude – the Cadillac was a discrete presence for its occupants, but it was a loud appearance for everyone outside the car. Not noisy, just impossible to ignore – and they are so to this day. Look at the original example starring in the video below (shot by Lou Costabile just a week ago) and put this next to any of Cadillac’s present models. Which one would you choose?