Steve Magnante's 1001 Corvette Facts. Steve Magnante

The 265 V-8 of 1955 was big news, but like 1953 and 1954, less sporty Powerglide automatic transmissions dominated production. Records show that between 70 and 80 of the 700 Corvettes built in 1955 received 3-speed manual transmissions. As for the final Blue Flame 6 models, even though GM sales literature hints that a 3-speed manual was available (the combination was used to establish the printed catalog base price), closer examination of the fine print shows the $178.35 Powerglide automatic to have been a “mandatory option.” The few manual-equipped V-8s were constructed in the second half of the model year.

      75 In later years, Corvette assembly workers were faced with a multitude of possible rear-axle ratios to install. But things were simple from 1953 to 1955, when open-type carriers and 3.55:1 gear sets were the rule. The first deviation came in 1955 when a 3.27:1 ratio arrived for late-year V-8 cars with the 3-speed manual transmission.

SUSPENSION AND BRAKES

      76 Corvette was the first Chevrolet passenger car to deviate from the division’s traditional torque-tube driveline, which was used from the start. Lead chassis designer Maurice Olley (a former Rolls-Royce employee) knew that passing a tube through the frame’s central X-member would force unacceptable drive-tunnel enlargement and infringe on space available for the bucket seats, a sports-car must. Corvette’s open driveshaft also simplified the art of driveline modification, quickly endearing it to hot rodders who began swapping engines, transmissions, and axles almost immediately.

      77 Another strike against the torque tube was the Corvette’s slight 102-inch wheelbase and severe engine setback. Less than 3 feet stood between the tail of the transmission and differential pinion. Attempting to stuff a rigid drive tube in the space was not workable on a car with sporting intent, where severe cornering loads triggered major shifts in the body-to-axle distance.

      78 The open driveshaft let the chassis designers take full advantage of the hypoid gear set’s positioning of the pinion gear on a lower axis than the center line of the ring gear. This lowered the driveshaft trajectory and allowed reduction of the driveshaft tunnel size for more interior room.

      79 Unlike previous Chevrolet practice that put the rear leaf springs inboard of, or directly below, the frame rails, Corvette springs were set outboard of the frame on outriggers. This allowed for much lower body placement and lowered the center of gravity for improved handling.

      80 The Corvette and its larger pre-1955 passenger-car siblings shared the same rear axle type but with alterations to the differential case to seal off the pinion bearing and accommodate an externally positioned universal joint and drive yoke. The “banjo” housing and bolt-on inspection cover were essentially unchanged except for variations to track width and spring mounts.

      81 For 1955, Chevy’s all-new passenger cars broke free from the torque-tube era. To handle the growing horsepower and torque of the V-8 age, a new rear axle housing with an integral (welded on) rear cover replaced the previous double-open housing of 1954. Interestingly, the new 1955 axle housing was not used on Corvettes until 1956. They retained the 10-bolt rear inspection cover for this final year.

      82 Ask any chassis designer and he’ll tell you: after jounce (downward force) comes rebound (upward bounce back). When proving-grounds tests revealed excessive rear-axle drop on Corvettes launched over steep moguls at speed, fabric rebound straps were added to limit damage to shock absorbers and universal joints. These straps ran from the ends of the axle tube to frame-mounted anchor points.

      83 Unlike most leaf-sprung American passenger cars with the rear shackles set under compression, the Corvette’s rear shackles were anchored to the frame below the leaf-spring eye. This put them in tension (as if being pulled apart rather than squashed). It was part of Olley’s recipe to set the leaf springs so their leading bushings/mounts were lower than their rearward counterparts (when viewed from the side). This manipulated the thrust angle of the axle and gave the Corvette a tendency toward predictable oversteer, which remained through the 1962 model run.

      84 By arranging the rear leaf springs as far outboard as possible and positioning the transmission high, Chevrolet was able to route the Corvette’s driveshaft high enough to avoid conflicts with the frame’s vitally important central X-member. Deviations in the design would have necessitated a driveshaft passage opening and a less rigid frame.

      85 The Corvette’s ladder-type steel frame featured fully boxed side rails not just in the middle region under the cockpit, like Chevrolet convertible passenger cars, but all the way to the horns on each end. The total weight was 213 pounds. For comparison, the fully assembled Corvette bare body weighed 340 pounds.

      86 To cut costs, the Corvette’s front suspension shared many passenger-car components. Again, it was ex–Rolls-Royce chassis guru Maurice Olley who oversaw adapting the Bel Air parts for use on the new sports car. Notable changes included specific steering linkage and revised front anti-sway bar positioning. Like all pre-1955 Chevrolet passenger cars, the Corvette employed kingpins instead of ball joints, a detail that hampered ideal handling until 1963 with the arrival of the Sting Ray.

      87 Power steering wasn’t offered on any Corvette until 1963, but to give the Corvette better reflexes in 1953, the Saginaw manual steering box was given a faster 16:1 ratio. The passenger-car steering ratio of the day was 19.4:1.

      88 The passenger-car parts bin also contributed major brake components to the Corvette program. The same 11 × 2.00/11 × 1.75-inch drums (front/rear) remained, but the piston in the brake master cylinder was 1/8-inch larger for quicker application. The brake proportioning valve was adjusted to deliver 3 percent less forward bias. This switch from the passenger car’s typical 56/44 (front/rear) to 53/47-percent proportion ratio was needed to complement the Corvette’s more even front/rear weight distribution.

      89 Chevrolet correctly predicted that “Midnight Auto Supply” crews would be highly attracted to the exciting new Corvette. To ease law enforcement’s efforts to identify purloined Corvettes, a hidden VIN stamping was applied to the top of the 1953 frame in addition to the stainless-steel VIN tag affixed to the driver-side door-hinge pillar. Visible through the driver-side rear wheel opening, the entire 10-character identification sequence was stamped atop the main frame rail where it transitioned upward over the axle. For 1954 and up, the hidden VIN was moved atop the central X-member near the driver’s seat and is almost impossible to read with the body in place.

      90 Long before the advent of cast- and forged-aluminum wheels, Corvette shared its unadorned 15 × 5-inch Kelsey Hayes steel rims with standard Chevrolets. The only detail setting them apart was color. All 1953 and 1954 rims were painted Sportsman Red to complement the interior. For 1955, Chevrolet shuffled the deck to suit the growing body color palette. Cars painted Gypsy Red (a different shade than Sportsman Red), Harvest Gold, and Corvette Copper received color-keyed rims. 1955 cars painted Polo White or Pennant Blue reverted to Sportsman Red wheels.

      91 The front side of Corvette’s steel wheels wore pretty shades of paint, but what about the reverse side? In a seemingly random fashion, some rims were painted to match the outboard face, and others were merely sprayed with a hasty coat of semi gloss black to prevent surface rust.

      92 A production hiccup forced the use of simple, bulbous 1953 Bel Air wheel covers on the first 25 Corvettes built in 1953. Or did it? Although there exist many GM photos of Bel Air–capped 1953 Corvettes, research indicates few, if any, reached showrooms with them. General Motors likely replaced them with the correct spinner-type covers before retail shipment.

      93 Although the bodies they carried differed dramatically, the frames underneath the Corvettes were almost the same from 1953 to 1962. The 11 body-mount locations, suspension geometry, and general characteristics remained unchanged. The most note-worthy change came in 1955 when the passenger-side frame horn received a stamped notch to clear the V-8’s protruding mechanical fuel pump.

      94 You had to stop and look for it, but the Corvette’s 58.8-inch rear track width was almost 2 inches wider than the 57.0-inch front measurement. This seeming mismatch