1934–1935 LaSalle Series 350: Oldsmobile-derived straight-eight and Knee-Action front suspension

Cadillac introduced the LaSalle Series 350 for 1934 with a 240.3-cubic-inch L-head straight-eight rated at 95 bhp, independent Knee-Action front suspension, and a 119-inch wheelbase. For 1935 the corresponding car became the Series 35-50, gained a nominal 248-cubic-inch engine rated at 105 bhp, and moved to a 120-inch wheelbase.

These were not simply restyled versions of the V-8 LaSalles that preceded them. General Motors replaced the Cadillac-derived V-8 with an engine developed from Oldsmobile practice, cut manufacturing costs, and wrapped the new chassis in some of the corporation's most assertive early streamline-era bodywork. The result helped reverse LaSalle's Depression-era sales decline while preserving a distinct visual identity beneath Cadillac in GM's divisional structure.

Best known for its narrow vertical grille, long hood, pontoon fenders, straight-eight engine, and dramatic departure from the upright 1933 cars, the 1934 Series 350 marked LaSalle's decisive transition into the streamlined era.

Quick Facts

The two model years share their basic engineering concept, but the factory series designation changed after 1934. That distinction matters when ordering parts, researching body numbers, or evaluating a supposedly original car.

The phrase “1934–1935 Series 350” is often used informally when grouping the two closely related years, but Series 350 is properly the 1934 designation. Cadillac's year-first numbering made the 1935 successor Series 35-50, a detail that should appear correctly in catalog descriptions and restoration records.

Why the 1934 LaSalle Series 350 Matters

The 1934 car mattered because it changed how LaSalle was built as well as how it looked. Earlier LaSalles drew heavily upon Cadillac V-8 engineering. The Series 350 substituted a less expensive straight-eight based on Oldsmobile architecture, allowing Cadillac to reduce production cost without turning LaSalle into a six-cylinder car or abandoning the refinement expected of the companion marque.

The new body was equally consequential. Its tall, thin grille leaned away from the broad, nearly upright radiator forms seen on many early-1930s automobiles. Long hood sides, tightly drawn fenders, lower body proportions, and a more integrated rear treatment made the 1933 LaSalle appear old almost immediately. The design gave buyers a clear reason to notice LaSalle at a time when Depression conditions had made discretionary luxury-car purchases exceptionally difficult.

Sales recovered substantially after the weak 1933 season, although surviving production totals can differ according to whether sources separate chassis, domestic bodies, exports, and calendar-year assemblies. The commercial response validated Cadillac's decision to retain LaSalle and rebuild it around less costly mechanical components.

Historical Context and Development

Cadillac, LaSalle, and the Depression market

General Motors created LaSalle for 1927 as a companion marque sold through Cadillac dealers. Harley Earl's original LaSalle also provided the institutional opening from which GM's Art and Colour Section developed. By the early 1930s, however, LaSalle faced pressure from two directions: depressed demand for prestige cars and increasingly capable medium-priced eights from Buick, Chrysler, Oldsmobile, and other manufacturers.

Cadillac could not treat the 1934 redesign as a routine facelift. The previous V-8 formula carried too much cost for the market LaSalle needed to reach. The straight-eight solution drew on engineering already available inside General Motors, while Cadillac retained responsibility for the complete automobile, its installation details, chassis tuning, body selection, and sales presentation.

Streamlining without abandoning formal proportions

The 1934 LaSalle did not pursue streamlining through an enclosed, teardrop body in the manner of the Chrysler Airflow. It retained a separate hood, distinct front and rear fenders, and recognizable body-on-frame construction. Its modernity came from proportion and surface treatment: a narrow grille, raked forms, cleaner hood sides, lower visual mass, and bodywork that appeared to flow around the passenger compartment.

This approach proved less commercially hazardous than the Airflow's unitary silhouette. Buyers received an unmistakably new car without losing the long hood, upright seating, prominent radiator form, and separate-fender vocabulary associated with an expensive American automobile.

No homologation or factory racing purpose

The Series 350 was not a homologation model, and Cadillac did not develop it around a formal factory competition program. Its engineering priorities were quietness, flexibility, manageable steering, ride quality, and production economy. Any surviving competition history generally concerns privately entered cars, endurance tours, or later historic events rather than a works racing campaign.

Engine and Drivetrain

The Series 350's defining mechanical change was its side-valve straight-eight. Its cylinders were arranged in one line, with the valves located in the block rather than in an overhead cylinder head. The layout was long but mechanically straightforward, with a smooth firing sequence and strong low-speed tractability suited to a heavy, high-geared road car.

The 1934 engine displaced 240.3 cubic inches and was factory-rated at 95 bhp. For 1935 Cadillac listed a larger, nominally 248-cubic-inch version at 105 bhp. Detailed bore, stroke, compression, and carburetor references are not entirely consistent across surviving manuals and later compilations, particularly where Oldsmobile specifications have been applied wholesale to LaSalle engines, so component-level restoration should begin with the correct Cadillac-LaSalle shop and parts literature.

A single downdraft carburetor supplied the naturally aspirated engine. Conventional distributor-and-coil ignition, liquid cooling with a belt-driven fan and water circulation, and pressure-fed lubrication reflected established GM practice. The cooling system's present condition matters more than its simplicity suggests because deposits, corroded water passages, tired pumps, and restricted radiator cores can make an otherwise healthy side-valve eight run hot.

Power passed through a dry single-plate clutch to a floor-shifted three-speed manual transmission, then through an enclosed propeller shaft to a live rear axle. Synchromesh reduced the skill required for shifts between the upper ratios, but first gear remained the ratio for starting and very slow work rather than a gear to be selected casually while moving.

The documented headline specifications are more useful than disputed minutiae when comparing complete cars:

Neither engine was intended to produce speed through high crankshaft revolutions. Its useful character lies in even torque delivery, smooth progress in the upper gears, and the ability to move a substantial body without constant shifting. A modern rebuild that sacrifices correct bearing clearances, cooling-system condition, or flywheel balance can lose precisely the smoothness that made the engine appropriate for LaSalle.

Chassis, Suspension, Steering, and Brakes

The 1934 redesign combined a separate steel body and frame with GM's independent Knee-Action front suspension. Each front wheel could respond to road movement independently, a considerable advance over the beam front axles still used by many American cars. The rear retained a conventional live axle located by semi-elliptic leaf springs.

Knee-Action was a commercial name applied to more than one GM front-suspension arrangement, so restorers should not assume interchangeability among Cadillac, LaSalle, Oldsmobile, Chevrolet, and Pontiac components. Wear in the support assemblies, pivots, seals, and damping mechanism can produce poor wheel control and vague geometry even when the car appears acceptable at low speed.

Steering remained unassisted and required deliberate input at parking speeds. Four-wheel internal-expanding mechanical brakes were used during these model years. A correctly rebuilt and equalized system is capable of orderly stops in period traffic, but cable or linkage wear, contaminated linings, distorted drums, and poor adjustment quickly create pulling and long pedal travel.

The major chassis figures establish the physical difference between the two years:

The additional inch of wheelbase in 1935 did not turn the 35-50 into a large Cadillac. Both cars remained relatively compact by contemporary prestige-car standards, while the independent front end gave them a less agitated ride over broken pavement than a comparable beam-axle chassis.

Driving Experience and Handling Dynamics

A sound Series 350 gathers speed rather than snapping forward. The straight-eight should pull cleanly from low engine speed, with a subdued exhaust note and little incentive to hold a gear to high revs. Weak compression, poor ignition timing, vacuum leaks, or an incorrectly set carburetor make the car feel considerably heavier than Cadillac intended.

The long inline engine and manual steering put weight over the front wheels. Steering effort is high while parking, eases once underway, and builds gradually rather than delivering modern rack-and-pinion precision. Excessive free play, shimmy, or a refusal to hold a line should not be dismissed as normal prewar behavior. Those symptoms usually point to steering-box wear, front-suspension deterioration, wheel balance, alignment, or loose chassis joints.

Knee-Action suspension gives the front axle a notably more independent response to ruts and transverse ridges. Body roll remains evident, and tall period-profile tires contribute their own compliance, but a properly sorted car should settle rather than continue oscillating. The live rear axle can step or patter over closely spaced bumps if the dampers and spring hardware are tired.

The three-speed transmission rewards measured movements and a pause through neutral. Upper-gear synchromesh makes ordinary touring manageable, while first gear and reverse still demand mechanical sympathy. Mechanical brake feel is firm and progressive when every drum, lining, pivot, rod, and compensating element is correct. One poorly adjusted corner can alter the car's behavior under braking far more than it would on a later hydraulic system.

Identification and Originality

Series 350 versus Series 35-50

A genuine 1934 car should be documented as Series 350, while the related 1935 model belongs to Series 35-50. The one-inch wheelbase change, body details, instruments, trim, lighting, hood treatment, and mechanical revisions should agree with the claimed model year. A title that merely says “LaSalle 350” is not enough to establish identity.

These cars predate the standardized 17-character VIN. Identification relies on period serial or engine numbers, frame markings where present and legible, and the Fisher or coachbuilder body plate carrying body-style, job, trim, and paint information. Locations and number formats should be checked against original Cadillac-LaSalle parts books, service literature, and recognized marque records rather than a generic online decoder.

Engine and body-number concerns

“Matching numbers” is a modern shorthand that can be misleading when applied to a 1934 automobile. A convincing car is one whose serial, engine, frame, body-style plate, casting characteristics, accessories, and documented history agree with the production period. Original sales paperwork, build information, old registrations, restoration photographs, and dated correspondence can be more persuasive than a newly stamped number.

The Oldsmobile relationship makes engine identification particularly important. A later Oldsmobile straight-eight or a later LaSalle unit may be made to fit, but mounts, manifolds, water connections, accessories, stampings, displacement, and external details can expose the substitution. The presence of a straight-eight alone does not prove that the engine is correct for either 1934 or 1935.

Body, trim, and finishes

Surviving open cars warrant careful examination because convertible coupes and convertible sedans command greater collector interest and can justify expensive reconstruction. The body-style number should correspond to the physical body. Door length, windshield posts, cowl structure, top mechanism, quarter panels, seat arrangement, and wood framing must make sense as a complete factory body rather than as parts assembled around an altered sedan chassis.

Correct paint and upholstery should be established from the body plate, factory color information, protected paint samples, and period trim references. Black engine-bay finishes, plated hardware, wood-grain interior treatments, instrument faces, rubber mats, broadcloth, leather, and top materials are frequently over-restored or replaced with generic modern substitutes. A brilliant finish cannot compensate for incorrect grain, stitching, plating, fasteners, or dashboard hardware.

Date coding was less comprehensive than on postwar cars, and consumable components such as glass, tires, hoses, belts, wiring, ignition parts, and exhaust pieces were expected to be replaced. Originality should therefore be judged through coherent period construction and documentation, not by insisting that every service item has survived from assembly.

Variant and Body-Style Breakdown

LaSalle offered open and closed Fisher-type production bodies rather than a homologation or factory competition derivative. Exact body-style terminology and availability should be confirmed in the relevant year's sales catalog because later advertisements often simplify club coupe, coupe, club sedan, and touring-sedan descriptions.

Published totals for individual body styles are not uniform across secondary sources, and some counts combine domestic, export, chassis-only, or calendar-year categories. For that reason, a precise rarity claim should be supported by factory production records or recognized LaSalle registry data for the exact body number.

Performance and Dimensions

Standardized acceleration testing was not yet routine, and body weight, axle ratio, road surface, fuel, and test method could alter period results substantially. Reliable model-wide 0-to-60 mph and quarter-mile figures are therefore not quoted here. Factory output and chassis dimensions provide the sounder basis for comparison.

Overall length and factory shipping weight differed by body style, especially between coupes, multi-passenger sedans, and open bodies. Top-speed figures in later reference works also vary and are often presented without axle-ratio or body information. A restored car's cruising ability should be assessed through engine condition, gearing, cooling capacity, tire specification, and brake adjustment rather than an isolated maximum-speed claim.

Compared With Related Cadillac and LaSalle Models

Against the 1933 LaSalle

The 1933 LaSalle belonged to the earlier V-8 lineage and retained more upright body architecture. The 1934 Series 350 brought the straight-eight, Knee-Action independent front suspension, a shorter and more modern visual package, and a far more pronounced streamlined treatment. Mechanically and aesthetically, the break is large enough that restoration knowledge does not transfer automatically between them.

Against the 1935 Series 35-50

The 35-50 is the direct development of the Series 350, not a separate companion line. Its wheelbase increased from 119 to 120 inches, nominal displacement rose from 240.3 to 248 cubic inches, and rated output climbed from 95 to 105 bhp. Styling and detail differences make year-correct trim important even though the cars share their fundamental straight-eight and independent-front-suspension formula.

Against contemporary Cadillac V-8s

Cadillac's senior cars retained V-8 power, larger chassis choices, more formal body selections, and a higher price structure. The LaSalle used fewer cylinders and drew more heavily on GM component sharing, but it was still assembled and marketed through the Cadillac organization. A LaSalle should not be restored as a Cadillac by adding senior-car emblems, hubcaps, instruments, or trim that do not match its body and series.

Against Buick and Chrysler eights

Buick offered overhead-valve straight-eight engines, while Chrysler's Airflow pursued a more radical integrated-body interpretation of streamlining. LaSalle's side-valve engine was less sophisticated in cylinder-head layout than Buick's, but its styling retained familiar luxury-car proportions. For collectors, the choice often comes down to LaSalle's Cadillac association and 1934 design, Buick's valvegear and model breadth, or the Airflow's structural and aerodynamic experimentation.

Ownership and Restoration Notes

Mechanical work

The inline-eight is durable when rebuilt to correct tolerances, supplied with clean oil, and kept cool. Age-related trouble commonly includes worn bearings, low compression, valve-seat recession or leakage, oil leakage, distributor wear, carburetor deterioration, restricted cooling passages, and corrosion within the radiator and water-jacket system. Long crankshaft and flywheel assemblies also demand competent balancing and alignment work.

A rebuild should not be handed to a shop solely because it understands later overhead-valve V-8s. Side-valve machining, poured or precision-fitted bearing work where applicable, valve geometry, oil-clearance control, and the inspection of a long crankshaft require prewar-engine experience. The correct LaSalle manual and parts list should remain on the bench throughout disassembly and assembly.

The three-speed gearbox is conventional but not immune to worn bearings, chipped teeth, tired synchronizers, bent shift components, and oil leakage. Clutch chatter can originate in the driven plate, flywheel, pressure plate, pilot support, engine mounts, or driveline alignment. Replacing only the friction lining may leave the underlying cause untouched.

Knee-Action suspension and brakes

The front suspension is one of the car's principal engineering features and one of its largest restoration liabilities. Complete inspection should include pivots, support members, seals, damping action, wheel bearings, steering linkage, and evidence of old welding or improvised conversions. Some cars were altered after original components became difficult to service, and reversing such work can require scarce castings and specialist machining.

Mechanical brakes need restoration as a complete system. Drum condition, shoe arc, lining material, cross-shafts, rods, clevises, pivots, return springs, and equalization all affect the result. A car with freshly lined shoes but worn linkage may still pull sharply or stop poorly.

Body structure and corrosion

Rust can attack lower doors, rocker and sill areas, floor edges, body mounts, wheel housings, fender attachment points, the cowl, and the rear body below the luggage area. Closed bodies may retain structural wood in doors, roof framing, or internal body sections, while open cars place greater demands on the sills, cowl, door alignment, and top structure. Sagging doors often indicate more than worn hinge pins.

Exterior brightwork, grille components, hood hardware, lamps, instruments, handles, wheel trim, and convertible top parts can cost more to restore than their size suggests. Reproduction support exists for selected service and cosmetic items, but it does not approach the depth available for mass-produced postwar American cars. Buying an incomplete project cheaply is rarely economical when several model-specific trim pieces are missing.

Service and preservation

Lubrication points, brake adjustment, ignition condition, coolant level, fan-belt tension, tire pressure, wheel-bearing adjustment, and gearbox and axle oil levels require regular attention. Service should follow the mileage and seasonal schedules in the period owner's and shop manuals rather than modern assumptions. Cars driven infrequently still need annual checks because condensation, fuel degradation, seal shrinkage, and corrosion continue while parked.

Buyer and Inspection Points

A serious inspection should establish identity and completeness before concentrating on paint quality. The following areas can separate a usable older restoration from a project requiring six-figure labor in body, trim, and mechanical work.

Drive the car from cold if possible. A pre-warmed engine can conceal difficult starting, low cold compression, bearing noise, carburetor drain-back, and slow oil-pressure response. The test should include uneven roads, repeated gear changes, a sustained climb, and several controlled stops, with attention paid to temperature, steering consistency, brake pull, and driveline vibration.

Collector and Market Relevance

Collectors distinguish the 1934 Series 350 from later LaSalles because it introduced the narrow-grille streamlined form and the straight-eight mechanical package in one model-year break. The 1935 Series 35-50 offers modestly greater output and a revised chassis while preserving much of the visual and engineering character that made the 1934 car commercially effective.

Open bodies generally attract the strongest attention, particularly when their body identity, top mechanism, and structural work are documented. Coupes have strong visual proportions and fewer body joints than convertibles, while sedans can offer the most practical route into prewar LaSalle touring. Condition and completeness frequently matter more than nominal body-style rarity because a missing grille casting, instrument, or convertible fitting can consume years of searching.

Auction buyers tend to reward correct stance, restrained paint, authentic upholstery, good panel fit, complete brightwork, and mechanical work supported by invoices. Modified engines, incorrect upholstery, modernized dashboards, poorly concealed front-suspension conversions, and vague number claims reduce confidence even when the exterior finish photographs well.

Cultural Relevance

The 1934 LaSalle belongs to the period when styling became a formal corporate discipline rather than a decorative operation performed after engineering had fixed the package. Harley Earl's organization used proportion, grille shape, fender form, and coordinated trim to make an annual model change immediately legible. LaSalle's recovery demonstrated that visual design could help revive demand even in a severely contracted luxury market.

The model's cultural life now centers on marque clubs, concours fields, preservation classes, touring events, and collections devoted to General Motors design. It has no substantial factory racing legacy and should not be given one retrospectively. Its contribution is found instead in industrial design, companion-marque strategy, and the development of an American luxury car that looked new without embracing the Airflow's more radical body architecture.

Period advertising and surviving promotional photography emphasized the narrow grille, long hood, and low silhouette. Those features still determine whether a restoration looks convincing. Incorrect tire proportions, overfilled wheel openings, an elevated front ride height, or excessively glossy trim can undermine the intended visual balance even when every individual part is present.

Frequently Asked Questions

Was the 1935 LaSalle officially called the Series 350?

No. Series 350 is the proper designation for the 1934 LaSalle. The directly related 1935 model was designated Series 35-50. Sellers and later summaries sometimes group both years under Series 350, but identification and parts research should use the correct year-specific series.

What engine did the 1934 LaSalle Series 350 use?

It used a naturally aspirated L-head inline-eight displacing 240.3 cubic inches and rated at 95 bhp. The design was derived from Oldsmobile straight-eight practice rather than the Cadillac V-8 used by preceding LaSalles.

How did the 1935 Series 35-50 differ mechanically?

The 1935 car used a nominal 248-cubic-inch version of the side-valve straight-eight rated at 105 bhp. Its wheelbase increased from 119 to 120 inches, while the basic front-engine, rear-drive layout, three-speed transmission, independent Knee-Action front suspension, and live rear axle continued.

How can a buyer identify a genuine Series 350?

Check the period serial or engine number, any surviving frame identification, the body-style plate, wheelbase, year-specific trim, and title against factory Cadillac-LaSalle literature. Because there is no standardized modern VIN, a conclusion should come from several agreeing identifiers rather than one stamped component.

Are 1934 LaSalle mechanical parts interchangeable with Oldsmobile parts?

Some engine architecture and selected components are related, but blanket interchangeability should not be assumed. LaSalle-specific mounts, manifolds, accessories, cooling connections, stampings, chassis pieces, and installation details can differ. Compare factory part numbers before purchasing or machining anything.

What are the most expensive restoration problems?

Severe body or structural deterioration, an incomplete open body, damaged Knee-Action suspension, a worn straight-eight, and missing grille, instrument, lamp, or top hardware create the largest bills. Chrome, wood framing, upholstery, and mechanical-brake restoration also become expensive because each requires considerable specialist labor.

What makes the 1934 Series 350 collectible?

It combines the first-year streamlined LaSalle body with the marque's shift from Cadillac-derived V-8 power to an Oldsmobile-derived straight-eight. That change records both GM's response to Depression economics and the growing authority of its styling organization. Correct, complete cars preserve a very specific turning point in Cadillac and LaSalle production.

Collector Takeaway

The 1934 Series 350 deserves attention because Cadillac changed the engine, suspension, proportions, and economic logic of LaSalle at the same time. The narrow grille and flowing fenders announced the new design in public, while the Oldsmobile-derived straight-eight and shared GM engineering made the car viable to manufacture during a punishing market contraction. The 1935 Series 35-50 then refined that formula with greater displacement, higher rated output, and a slightly longer wheelbase.

Buy the most complete and best-documented example rather than the shiniest one. A correct grille, sound Knee-Action front end, authentic body plate, proper straight-eight, intact trim, and honest structural restoration define these cars far more convincingly than deep paint. When those elements are right, the Series 350 explains in metal why LaSalle survived 1934 and why General Motors styling gained such influence over the American automobile.