The 1958 Chevrolet Impala is where one of the most famous nameplates in American motoring began — and it began not as a model but as a trim. For 1958 the Impala was the top-of-the-line Bel Air, offered only as a two-door Sport Coupe and a convertible, and distinguished from every other Chevrolet by its symmetrical triple taillights. The year brought an entirely new X-frame chassis, coil-spring rear suspension, dual headlamps for the first time, and — most consequentially — the 348 cu in Turbo-Thrust V8, the first Chevrolet big-block ever built. The 1958 body was used for one year only, which makes it the rarest-looking Impala of all.
Table of Contents
- Overview and History
- A Trim Level, Not a Model
- Body Styles
- Styling and the One-Year Body
- The New X-Frame Chassis
- The First Chevrolet Big-Block
- Full Engine Lineup
- Transmissions
- Interior and Equipment
- Production and Market
- Collectibility Today
- Key Features Summary
- Full Specifications Table
Overview and History
1958 was General Motors’ fiftieth anniversary, and the corporation marked it by introducing a special halo model for each division: the Pontiac Bonneville Catalina, the Buick Limited Riviera, the Oldsmobile Starfire 98, the Cadillac Eldorado Seville — and, for Chevrolet, the Bel Air Impala.
The name itself was not new. Impala had first appeared on a 1956 General Motors Motorama show car, and Chevrolet revived it for the production flagship. What arrived in showrooms was a substantially different car from the 1957 Chevrolet that preceded it: an all-new body, an all-new chassis, a new coil-sprung rear suspension, dual headlamps, and the division’s first big-block V8.
The timing was awkward. 1958 was a recession year in the United States, and the car market contracted sharply. Despite that, Chevrolet sales rose and the division overtook Ford, which had held the top position in 1957. The Impala sold strongly for a premium model, with 125,480 Sport Coupes and 55,989 convertibles finding buyers.
The Impala would become its own separate series for 1959 and go on to be the best-selling car in America for much of the 1960s. But everything that followed traces to this one year.
A Trim Level, Not a Model
This is the single most important fact to understand about the 1958, and it is routinely stated incorrectly. The Impala was not a separate series in 1958. It was the top-of-the-line version of the Bel Air, available only in two body styles.
Curiously, although the car was technically a Bel Air, “Bel Air” series badging was absent from the car itself, from the sales literature, and from the advertising. Chevrolet marketed it simply as the Impala, which is a large part of why the distinction is so often forgotten.
The Impala was also structurally different from the cars below it. From the windshield A-pillar rearward, the 1958 Impala differed structurally from the lower-priced Chevrolet models — it was not merely a trim package applied to a standard body. That structural separation is part of why the Impala became a full series the following year.
Chevrolet’s 1958 range ran, from bottom to top: Delray (the price leader), Biscayne, Bel Air, and the Bel Air Impala at the summit.
Body Styles
The Impala was offered in exactly two body styles for 1958:
- 2-Door Sport Coupe — the pillarless hardtop, and by far the volume seller
- 2-Door Convertible
There was no four-door Impala, no Impala sedan, and no Impala wagon in 1958. Any 1958 Chevrolet four-door is a Bel Air, Biscayne, or Delray, not an Impala — a useful check when evaluating a car’s described identity. The four-door Impala bodies would arrive for 1959, when the Impala became its own series.
Styling and the One-Year Body
The 1958 body was used for a single model year. The 1957 Chevrolet had been the end of the Tri-Five line, and the 1959 brought the radical batwing restyle — so the 1958 stands alone, sandwiched between two far more famous designs.
The shape was longer, lower, and wider than the 1957, with heavy chrome, a broad grille, and — a first for Chevrolet — dual headlamps on each side, which had become the fashion across the industry. The Impala’s defining visual signature was at the rear: symmetrical triple taillights, three round lamps on each side, where lesser 1958 Chevrolets used two per side. That six-lamp arrangement became an Impala identifier for years afterward.
The Impala also carried unique rear quarter trim, a distinctive roofline on the Sport Coupe, crossed-flag Impala badging, and generous brightwork that marked it clearly as the flagship. Because the body was used only in 1958, reproduction sheet metal and trim are far scarcer than for the Tri-Five or the 1959–60 cars — a genuine consideration for anyone restoring one.
The New X-Frame Chassis
Beneath the sheet metal, 1958 brought an entirely new chassis. Chevrolet adopted an X-frame design similar in layout to the frame used on the 1957 Cadillac, with box-section side rails and a boxed front cross member that bowed under the engine. The same basic architecture would serve Chevrolet from 1958 through 1964.
The X-frame was lower than the perimeter frames it replaced, allowing the dramatically lower bodies the era demanded. Its weakness — much discussed since — is the absence of side rails outboard of the passenger compartment, which offered less protection in a side impact.
Equally significant was the suspension. A coil-spring rear suspension replaced the previous leaf-sprung arrangement, a meaningful ride improvement and a layout Chevrolet would keep for decades. A quirky optional Level Air air suspension was also listed in its second and final year, but it was unreliable, expensive, and almost never seen; a surviving car with functioning factory air suspension is a genuine curiosity.
The First Chevrolet Big-Block
The headline mechanical news of 1958 was the 348 cu in Turbo-Thrust V8 — the first version of the Chevrolet big-block engine, known as the W-series.
The engine had been designed originally for truck use, and it was introduced into the larger, heavier 1958 passenger car line because the small-block simply did not have the displacement for a car of this size and weight. It is instantly recognizable by its oddly shaped valve covers, which are not rectangular but resemble a letter “W” or a sideways “E” — hence the W-series name.
For 1958 the 348 was offered in three states of tune: 250 hp with a four-barrel carburetor, 280 hp, and a top 315 hp version using three two-barrel carburetors — the famous Tri-Power setup. A 315 hp rating was a stellar figure for 1958.
The 348’s significance extends well beyond this one year. It was superseded by the 409 as Chevrolet’s top engine in 1961 and went out of production for cars at the end of that year, continuing in light trucks through 1964. The 409 that the Beach Boys made famous was a bored and stroked evolution of this engine. Everything in Chevrolet’s big-block performance story starts with the 1958 348.
Full Engine Lineup
The 1958 range was unusually broad:
- 235 cu in Blue Flame six — the standard engine
- 283 cu in V8, 2-barrel — approximately 185 hp
- 283 cu in V8, 4-barrel — 230 hp and 250 hp versions
- 283 cu in V8, fuel injection — 290 hp, the Ramjet system carried over from 1957
- 348 cu in V8, 4-barrel — 250 hp
- 348 cu in V8, Tri-Power — 280 hp
- 348 cu in V8, Tri-Power high output — 315 hp
Fuel injection remained available on the 283 but was expensive and rare, and the arrival of the cheaper, torquier 348 made it a harder sell in a big car. A fuel-injected 1958 Impala is an exceptionally rare find and demands rigorous verification.
Transmissions
Three transmissions were offered:
- Three-speed manual — standard, column shifted
- Powerglide — the familiar two-speed automatic
- Turboglide — a more complex three-speed-equivalent automatic available with V8 engines
Turboglide deserves a note of caution. It offered smoother, more continuous acceleration than Powerglide but was complicated, difficult to service, and earned a poor durability reputation. Many were replaced with Powerglide units over the years. On a car you intend to drive, a Powerglide or manual is the easier proposition; an original working Turboglide is correct but needs a specialist.
Period testing recorded a 348-powered four-door with Turboglide reaching 60 mph in about 13.1 seconds — respectable for a large 1958 car, and considerably quicker in the lighter Impala Sport Coupe with a manual.
Interior and Equipment
The Impala’s cabin was the most lavish Chevrolet offered. Standard equipment went well beyond the Bel Air, with richer upholstery combinations, distinctive door panel treatments, a deluxe steering wheel, and extensive bright interior trim.
Options included power steering, power brakes, power windows, power seats, air conditioning, a radio, a clock, tinted glass, whitewall tires, full wheel covers, and a range of two-tone paint combinations. A well-optioned 1958 Impala convertible was among the most expensive cars Chevrolet sold, and it felt the part.
Production and Market
Impala production for 1958 broke down as:
- 2-Door Sport Coupe: 125,480
- Convertible: 55,989
Those are strong numbers for a premium trim in a recession year, and they explain why Chevrolet promoted the Impala to a full series for 1959. Total Chevrolet production was sufficient to take the division past Ford for the model year.
Worth noting for context: the Bel Air remained the most popular Chevrolet model overall in 1958. The Impala was the glamour car, not the volume car — a position it would reverse within a few years.
Collectibility Today
The 1958 Impala occupies an unusual place in the market. It is overshadowed by the Tri-Five cars that preceded it and the dramatic 1959 that followed, which has historically kept values below both — yet it is the first Impala, it carries the first Chevrolet big-block, and its body was built for a single year.
The convertible leads values, followed by the Sport Coupe. A 348-powered car commands a clear premium over a 283 or a six, and a Tri-Power 315 hp example more so again. Documented fuel-injected cars are in a category of their own.
The practical challenge is parts. Unlike the Tri-Five Chevrolets, which enjoy one of the largest aftermarkets in the hobby, the one-year 1958 body means sheet metal, trim, and glass are far harder to source and often require original used parts or specialist reproduction. Inspect carefully for rust in floors, lower quarters, trunk, and around the rear window, and budget realistically — a rough 1958 is a much more expensive project than a rough 1957.
Key Features Summary
- Significance: The first Impala — GM’s 50th anniversary halo model for Chevrolet
- Status: Top-of-the-line Bel Air trim, not a separate series
- Body Styles: 2-door Sport Coupe and convertible only
- Identifier: Symmetrical triple taillights (three per side)
- Body: Used for one model year only
- New Chassis: X-frame, used by Chevrolet 1958–1964
- New Suspension: Coil-spring rear, replacing leaf springs
- Lighting: First Chevrolet year with dual headlamps
- Landmark Engine: 348 cu in Turbo-Thrust — the first Chevrolet big-block (W-series)
- 348 Outputs: 250, 280, and 315 hp (Tri-Power)
- Other Engines: 235 six; 283 V8 up to 290 hp fuel-injected
- Transmissions: 3-speed manual, Powerglide, Turboglide
- Production: 125,480 Sport Coupes; 55,989 convertibles
- Range Position: Above Delray, Biscayne, and Bel Air
The 1958 Chevrolet Impala Specs
| BODY | |
| Manufacturer | Chevrolet (General Motors) |
| Status | Top trim of the Bel Air series — not a separate model |
| Body Styles | 2-door Sport Coupe (hardtop); 2-door convertible |
| Badging Note | “Bel Air” badging absent from car, literature, and advertising |
| Structural Note | Differs structurally from lesser models from the A-pillar rearward |
| Body Production Span | 1958 only |
| Range Hierarchy | Delray → Biscayne → Bel Air → Bel Air Impala |
| Occasion | GM 50th anniversary model for Chevrolet |
| STYLING IDENTIFIERS | |
| Taillights | Symmetrical triple (three per side); lesser models used two |
| Headlamps | Dual — first Chevrolet year |
| Badging | Crossed-flag Impala emblems |
| CHASSIS AND SUSPENSION | |
| Frame | X-frame, box-section side rails, boxed front cross member |
| Frame Lineage | Similar to 1957 Cadillac; used by Chevrolet 1958–1964 |
| Front Suspension | Independent, coil springs |
| Rear Suspension | Coil springs — new for 1958, replacing leaf springs |
| Optional Suspension | Level Air air suspension — second and final year, very rarely seen |
| Steering | Recirculating ball; power assist optional |
| Brakes | Drums front and rear; power assist optional |
| ENGINE — STANDARD (235 Blue Flame Six) | |
| Engine Type | OHV inline-6 |
| Displacement | 235 cu in (3.9 L) |
| ENGINE — 283 V8 | |
| Displacement | 283 cu in (4.6 L) |
| 2-barrel | approx. 185 hp |
| 4-barrel | 230 hp and 250 hp |
| Fuel Injection | 290 hp — Ramjet, rare |
| ENGINE — 348 TURBO-THRUST V8 (first Chevrolet big-block) | |
| Displacement | 348 cu in (5.7 L) |
| Bore × Stroke | 4.125 × 3.25 inches |
| Family | W-series big-block |
| Origin | Originally designed for truck use |
| 4-barrel | 250 hp, approx. 355 lb·ft |
| Tri-Power (3×2 bbl) | 280 hp, approx. 355 lb·ft |
| Tri-Power High Output | 315 hp, approx. 356 lb·ft |
| Identification | Distinctive W-shaped valve covers |
| Successor | 409 cu in from 1961 — a bored and stroked 348 |
| TRANSMISSION | |
| Standard | 3-speed manual, column shift |
| Optional | Powerglide 2-speed automatic |
| Optional | Turboglide automatic (V8) — complex, poor durability record |
| PERFORMANCE | |
| 0–60 mph (348/280 hp, Turboglide, 4-dr) | approx. 13.1 seconds (period test) |
| Character | Quicker in the lighter Impala Sport Coupe with manual |
| PRODUCTION (1958) | |
| Impala Sport Coupe | 125,480 |
| Impala Convertible | 55,989 |
| Market Context | Recession year; Chevrolet nonetheless overtook Ford |
| Most Popular Chevrolet Model | Bel Air |
| OPTIONAL EQUIPMENT (SELECTED) | |
| 348 Turbo-Thrust V8 | Opt. — the defining option |
| Tri-Power Induction | Opt. |
| Ramjet Fuel Injection (283) | Opt. — rare |
| Powerglide / Turboglide | Opt. |
| Level Air Suspension | Opt. — final year, almost never ordered |
| Power Steering / Power Brakes | Opt. |
| Power Windows / Power Seats | Opt. |
| Air Conditioning | Opt. |
| Radio and Clock | Opt. |
| Tinted Glass | Opt. |
| Whitewall Tires / Full Wheel Covers | Opt. |
| Two-Tone Paint | Opt. |
1958 Chevrolet Impala – Frequently Asked Questions
Was the 1958 Impala a separate model?
No. In 1958 the Impala was the top-of-the-line version of the Bel Air, offered only as a two-door Sport Coupe and a convertible. Oddly, “Bel Air” badging was absent from the car, the literature, and the advertising, so Chevrolet effectively marketed it as the Impala. It became its own separate series for 1959. Any 1958 Chevrolet four-door is therefore a Bel Air, Biscayne, or Delray — never an Impala.
How do I identify a 1958 Impala?
The quickest tell is the rear. The Impala uses symmetrical triple taillights — three round lamps on each side — while lesser 1958 Chevrolets used two per side. It also carries crossed-flag Impala badging, unique rear quarter trim, and more brightwork. The body style must be a two-door Sport Coupe or a convertible.
What is the 348 engine in a 1958 Impala?
The 348 cu in Turbo-Thrust V8 is the first Chevrolet big-block, the beginning of the W-series family. It was originally designed for truck use and introduced in the heavier 1958 passenger cars. For 1958 it came in 250 hp (four-barrel), 280 hp, and 315 hp (Tri-Power) forms. It is recognizable by its distinctive W-shaped valve covers, and it was the direct ancestor of the famous 409.
What is the X-frame and is it a problem?
The X-frame was the new chassis introduced for 1958, similar in layout to the 1957 Cadillac frame and used by Chevrolet through 1964. It allowed the much lower bodies of the era. Its known weakness is the lack of side rails outboard of the passenger compartment, which offers less protection in a side impact than a perimeter frame. It is a consideration worth understanding, not a reason to avoid the car.
Why is the 1958 body unusual?
Because it was used for one model year only. The 1957 ended the Tri-Five run and the 1959 brought the radical batwing restyle, leaving the 1958 standing alone between two far more famous designs. The practical consequence is that sheet metal, trim, and glass are much harder to source than for Tri-Five or 1959–60 cars, which makes a rough 1958 an expensive restoration.
How many 1958 Impalas were built?
125,480 Sport Coupes and 55,989 convertibles — strong figures for a premium trim in what was a recession year in the United States. Chevrolet’s overall sales nonetheless rose enough to overtake Ford for the model year, though the Bel Air remained the division’s most popular model.
Should I avoid a Turboglide transmission?
Be cautious. Turboglide was the more sophisticated automatic offered with V8 engines, giving smoother and more continuous acceleration than Powerglide, but it was complex, hard to service, and developed a poor durability reputation. Many were replaced over the years. An original working Turboglide is correct and interesting but needs a specialist; a Powerglide or manual car is easier to live with.
Is a 1958 Impala a good classic to buy?
It has real appeal — first-year status, the first Chevrolet big-block, and a one-year-only body — and it has historically been priced below both the Tri-Five cars and the 1959. Convertibles lead values, with 348 Tri-Power cars commanding premiums. The caveat is parts availability: there is no large aftermarket as there is for the Tri-Five, so buy the most solid car you can find rather than planning a major restoration.
