The early days of the young firm were difficult ones and the brothers made two initial, important decisions: firstly that the cars would be built slowly and with the greatest care and attention, secondly that they would manufacture as many components as possible themselves to avoid dependence on outside suppliers. David decided to use the Chevrolet V-8 327 cu. inch 300hp engine and to make the body panels from glass fibre rather than aluminum. The radiator grilles would be aluminum castings rather than copper as on the prototype. Meanwhile, Steve Stevens was organizing chassis production in the family workshop in Mequon, Wisconsin. In the first year of production the chassis were transported by truck to Milwaukee, where the bodywork was fabricated and the Excaliburs were assembled. In January of 1966 the firm moved to the West Allis Industrial zone.

The Excalibur SI was initially available only in a two-seater Roadster version as designed by Brooks Stevens. But by mid 1966 the company had built 56 automobiles and introduced two more models: an elaborated Roadster with longer mudguards and running boards, and a convertible four-seater known as the Phaeton. Excalibur built exactly 90 cars during 1966 and production didn’t reach 100 units in a year until 1969 – the same year that SI production was stopped.

By 1970, Excalibur were well established but had engendered the birth of numerous imitators who were helping satisfy the demands of a market that the limited Excalibur production alone could not. The Stevens brothers didn’t want to increase their production rate for fear it would adversely affect the impeccable build quality that they wanted the public to enjoy. So they launched the Excalibur Series II, an all new car despite the fact that it perpetuated the S1 styling. As the old Studebaker Lark chassis was no longer built, David designed a new ladder chassis which had a 2 inch longer wheelbase. The suspension components ere borrowed from the Corvette, as was the four-disc braking system. Tire size went up and the rubbers were mounted on wheels especially designed for the car. The 327 ci. inch (5400 cc) V-8 engine bowed down to the new 350 cu. inch (5700 cc) unit which, with its anti-pollution equipment still managed to develop a healthy 300 hp. The “Muncie” four-speed manual transmission became standard, with a Turbo-Hydramatic three-speed unit available as an option.

From a price of $6000-$7250 for the S1, the Excalibur SII went up to $12,000 -$13,000 but justified that extra cost with its supplementary equipment. This included air conditioning, variable ratio power steering, adjustable steering column, brakes, “Positraction” differential, chromed wire wheels, stereo radio, two spare tires mounted in the front fenders, driving lamps, air horns and constant level rear shock absorbers. Despite the added mass of this luxurious equipment, the Excalibur Series II was capable of really sporting performance: 0-60 mph in under 7 seconds and a top speed of 149 mph! Unfortunately the production figures showed a steep decline at first with only 37 cars in 1970 and none whatsoever in 1971. What happened next is quite inexplicable, for from a production of zero in 1971, the figure rose to 122 the next year. Today the Excalibur Series II remains the rarest of all Excaliburs, with a total production number of only 342 against the Series I’s 359.

The reason; David and Steve decided to retool the chassis and install a new engine. The first few series II cars built in 1970 had a box type rear frame section with a Chevrolet Camero front frame stub bolted on. Then in 1972 the chassis was a new one, although still a ladder-type affair, reinforced by a central ‘X’-shaped member and featuring a removable bolt-on front section. Wheelbase had once more been stretched to 112 inches and the whole new chassis assembly housed an equally new engine…a Chevy Mk IV 454 cu. inch (7500 cc) big-block V8 which, were being used in the corvettes at the time. They offered the power to go with the looks. This was used through 1974.

Starting in 1975 despite its generous cylinder capacity, the 454 was essentially now a truck engine and produced only a humble 215 hp SAE due to the stifling anti-pollution equipment fitted. Cruise control was now standard.

Today, the 1970 Excalibur Series II remains the rarest of all Excaliburs, with a total production number of only 37 cars 11 Roadsters and 26 phaetons.