1937–1940 LaSalle Convertible Coupe: Cadillac’s 322-Cubic-Inch V8

LaSalle sold the Convertible Coupe from 1937 through 1940 with Cadillac’s 322-cubic-inch L-head V8, rear-wheel drive, and a three-speed manual transmission. Factory ratings were 125 bhp for 1937 through 1939 and 130 bhp for 1940, while the open Fisher body appeared in Series 50 form throughout the period and also in the streamlined Series 52 range for 1940. These were the final four model years of Cadillac’s companion marque before LaSalle disappeared after 1940.

Best known for reuniting LaSalle with Cadillac V8 power after the Oldsmobile-derived straight-eight years of 1934 through 1936, the late Convertible Coupe combines a short-production open body with the mechanical architecture of contemporary Cadillac models. Collectors care about it because a properly identified example captures both the end of LaSalle and General Motors’ rapid transition from upright mid-1930s styling to the lower, wider forms that defined the 1940s.

The term Companion Marque Final Era describes this 1937 to 1940 generation neatly, though it was not a factory series designation. Cadillac continued to present LaSalle as a separate marque, with its own grille treatment and badging, while sharing engines, engineering resources, Fisher body practice, and dealer infrastructure with Cadillac.

Quick Facts

The essentials below separate the late V8 Convertible Coupe from earlier LaSalles and identify the two factory series encountered in the final model year.

The 322 V8 is the central dividing line in late LaSalle history. A seller describing a 1937 through 1940 car with the preceding straight-eight drivetrain is either dealing with a major conversion, an incorrectly dated car, or an inaccurate listing.

Why the Final-Era Convertible Coupe Matters

Cadillac restored a genuine Cadillac engine to LaSalle for 1937. That decision removed the most obvious mechanical distinction between LaSalle and the lower-priced Cadillac series, giving the companion marque Cadillac’s compact monobloc V8 while retaining separate styling, trim, and pricing.

The Convertible Coupe also records a disappearing body format. It combined a folding fabric roof, a close-coupled passenger compartment, a separate luggage compartment, and proportions more sporting than the volume-selling sedans. Open bodies sold in smaller numbers, suffered harder use, and were more vulnerable to weather, structural corrosion, and later modification, all of which make complete survivors especially valuable to restorers.

There was no homologation requirement and no factory competition program behind the model. Its historical case rests instead on production engineering, body design, and corporate history: the late Convertible Coupe was one of the last open cars to carry the LaSalle crest before Cadillac replaced the marque’s commercial function with lower-priced Cadillac series.

Historical Context and Development

From Harley Earl’s Companion Marque to a Cadillac-Powered Finale

General Motors introduced LaSalle for 1927 under Cadillac management. The original cars are closely associated with Harley Earl’s arrival at GM and with the corporation’s effort to create distinct marques at graduated prices. By the middle of the 1930s, however, the Depression had compressed the luxury market and made overlap between LaSalle, Buick, and entry-level Cadillac models increasingly difficult to justify.

The 1934 through 1936 LaSalles used a straight-eight derived from Oldsmobile engineering. For 1937, Cadillac installed its 322-cubic-inch V8, a compact L-head design introduced in the Cadillac range for 1936. The change made the new LaSalle mechanically closer to Cadillac while a longer, lower body and a sharply defined grille maintained a separate visual identity.

LaSalle met the Packard One-Twenty, Lincoln-Zephyr, and larger Buick models in a market where prestige alone could not secure a sale. Buyers expected hydraulic brakes, easier steering, synchronized shifting, independent front suspension, and closed-car refinement. The Convertible Coupe added open-air appeal but retained the same basic chassis engineering as the sedans and coupes.

Styling from 1937 to 1940

The 1937 design carried a tall, narrow grille, flowing front fenders, exposed running boards, and headlights placed as distinct elements rather than fully absorbed into the body. Its hood and body sat visibly lower than those of earlier LaSalles, and the convertible’s short greenhouse emphasized the long hood and rear deck.

Successive revisions integrated the lamps and fenders more closely. The 1938 and 1939 cars adopted broader, more horizontal visual themes while retaining a recognizable LaSalle grille. For 1940, the Series 52 applied the newer torpedo-body vocabulary, with a more integrated envelope and reduced visual separation between fenders and body. Sealed-beam headlamps also identify the 1940 model year.

Interiors followed Cadillac practice in their use of a broad instrument panel, large steering wheel, bright metal controls, and substantial upholstery. Correct grain, stitching, seat construction, rubber components, and plated hardware matter greatly because a generic modern retrim can erase much of the cabin’s period character.

Engine and Drivetrain

All four model years used Cadillac’s 322-cubic-inch, 90-degree V8. The engine employed side valves in an L-head arrangement, a cast-iron block, detachable cylinder heads, and three main crankshaft bearings. Its 3.375-inch bore and 4.5-inch stroke favored low-speed pulling ability over high engine speed.

Period torque and engine-speed limits are not consistently published in comparable form, so they are better omitted than reconstructed from later estimates. The factory horsepower increase for 1940 was modest, and the engine’s defining behavior remained a broad supply of low-speed torque delivered through conservative gearing.

A single dry-plate clutch connected the V8 to the selective three-speed gearbox. Synchronization eased shifts in the upper ratios, although these transmissions still reward deliberate movements and a pause during cold operation. The 1937 car retained a conventional floor-mounted lever, while the steering-column Safety Shift appeared for 1938 and continued thereafter.

Fuel reaches the downdraft carburetor through a mechanical pump. The cooling system uses belt-driven water circulation, and the pressure-lubricated engine depends on clean oil passages and sound bearing clearances. Modern restorations often conceal electric fuel pumps or cooling aids, but such additions should be installed reversibly and documented.

Chassis, Suspension, and Braking

The Convertible Coupe used separate body-and-frame construction, with Fisher bodywork mounted to a substantial steel frame. Open bodies lack the fixed steel roof that helps a sedan resist torsional movement, so floor structure, sills, body mounts, and door openings are critical to both alignment and road behavior.

Independent front suspension gave the LaSalle better wheel control over broken surfaces than a rigid front axle, while the long wheelbase and compliant springing suited American roads. Hydraulic drums were modern equipment for the class, but their effectiveness now depends on round drums, uncontaminated linings, sound hoses, correctly rebuilt cylinders, and careful adjustment.

Driving Experience and Handling Dynamics

A healthy 322 starts with a muted mechanical rhythm and pulls away without demanding high revs. Throttle response is progressive rather than sharp, and the tall gearing encourages the driver to use the engine’s low-speed flexibility. The V8 is happiest when short-shifted and allowed to gather speed rather than being held against the upper end of its range.

At parking speed the steering is heavy, particularly with underinflated or oversize tires. Once moving, effort falls away and the long wheelbase lends stability, though the slow steering and narrow bias-ply tires require anticipation. A correctly rebuilt front end should track cleanly; wandering, shimmy, or persistent steering kickback usually points to wear, alignment errors, wheel imbalance, or inappropriate tires.

The suspension permits visible roll and pitch by modern standards, but that movement should be controlled rather than loose. Convertible body shake is possible on rough surfaces, yet severe scuttle movement or changing door gaps suggest weakened body mounts, floor structure, or frame damage rather than an inherent trait to be accepted.

The gearbox works best with an unhurried hand. Column-shift cars need unworn linkage and correctly adjusted rods to avoid crossed or incomplete engagement. Drum brakes provide usable stopping power in period traffic when properly set up, but repeated hard stops generate heat and fade much sooner than a modern disc system.

Identification and Originality

Serial Numbers, Fisher Tags, and Body Style Codes

These cars predate the standardized 17-character VIN. Identification begins with the period vehicle serial or engine number, the frame stamping where present, and the Fisher Body data plate. The body plate records information such as model-year style, body sequence, trim, and paint, but its layout and abbreviations must be checked against documentation for the specific year.

The Fisher style designation is particularly useful. Series 50 Convertible Coupes are generally associated with body style 5067, while the 1940 Series 52 Convertible Coupe uses 5267, normally accompanied by a model-year prefix on the body tag. A tag showing a sedan or closed-coupe style number on an open car deserves immediate investigation.

Engine-number practice on prewar Cadillacs and LaSalles makes the phrase matching numbers less straightforward than it is on a later muscle car. The buyer should establish whether the installed engine carries the correct type and a number consistent with the car’s serial identity and production period. A restamped pad, missing frame number, replacement data plate, or newly reproduced tag requires documentary support, not a verbal explanation.

Correct Components and Finishes

Inspect the grille, hood side trim, wheel covers, dashboard, gauges, steering wheel, lamps, handles, and emblems against year-specific factory literature. These pieces changed more often than the basic engine, and restoration projects were frequently completed with whatever Cadillac or LaSalle parts could be sourced at the time.

Carburetors, distributors, generators, starters, voltage regulators, glass markings, and lighting equipment can carry manufacturer or date information. A component dated slightly before final assembly may be entirely appropriate; a collection of postwar electrical parts is not. Date evidence should support the whole car rather than being treated as proof in isolation.

Paint and trim numbers should be interpreted from the original Fisher plate and the correct model-year charts. Surviving paint under hinges, behind garnish moldings, beneath weather seals, or inside the cowl can confirm the original color. Metallic pigments, upholstery grain, top material, and carpet construction are difficult to reproduce accurately without period samples.

Variant and Trim Breakdown

The Convertible Coupe changed in appearance and chassis dimensions across four model years, but not in basic engine architecture. The 1940 Series 52 is the principal same-year variant that must be distinguished from Series 50.

Exact Convertible Coupe production totals are not consistently reported across surviving summaries, especially where 1940 Series 50 and Series 52 figures are combined or separated differently. Body tags and factory records should therefore carry more weight than unsupported rarity claims in advertisements.

Performance and Dimensional Specifications

Factory literature provides dependable rated output and wheelbase data, but standardized acceleration tests were uncommon and period weight figures may refer to shipping weight rather than a fully equipped road car. The table therefore avoids presenting reconstructed 0–60 mph, quarter-mile, curb-weight, or top-speed numbers as factory facts.

Road performance depends heavily on axle ratio, tire diameter, engine condition, and body equipment. Period accounts generally describe road speed appropriate to American touring rather than sports-car acceleration. Any precise performance claim should identify its source, test conditions, body style, and gearing.

Compared With Related Models

1934–1936 LaSalle

The immediate predecessors used an inline eight derived from Oldsmobile engineering. The 1937 redesign brought the Cadillac 322 V8, different proportions, and a more direct mechanical relationship with Cadillac. That engine difference is fundamental when evaluating parts cars, advertisements, and partially completed restorations.

Cadillac Series 60 and Series 61

Contemporary lower-series Cadillacs shared much of the V8 engineering, but carried Cadillac identification, trim, and body details. Interchange can make a Cadillac component mechanically useful without making it correct for a LaSalle. Grilles, instruments, moldings, wheel covers, and badging should never be assumed interchangeable merely because the engine family is shared.

For 1941, there was no LaSalle. Cadillac’s Series 61 performed much of the commercial role that the companion marque had filled, now under Cadillac badging. The 1940 Convertible Coupe is therefore a true terminal-year car, not simply the predecessor to a restyled 1941 LaSalle.

Packard One-Twenty and Lincoln-Zephyr

The Packard One-Twenty paired an inline eight with hydraulic brakes and independent front suspension, making it a close period rival in price and purpose. Lincoln’s Zephyr used a V12 and unitized construction, a sharply different engineering route wrapped in more overtly aerodynamic styling. The LaSalle answered with Cadillac’s compact V8, conventional body-on-frame construction, and established Cadillac dealer service.

Ownership and Restoration Notes

The 322 V8 is durable when cooling passages, oil delivery, bearing clearances, and ignition are correct. Long-stored engines may conceal stuck valves, corroded water jackets, degraded fuel-system diaphragms, and sludge in the crankcase. Before attempting repeated starts, inspect the oil, verify free rotation, test the cooling system, and assess fuel contamination.

A proper rebuild requires a machine shop familiar with prewar side-valve engines and poured or precision-fitted bearing work as applicable to the components being serviced. Crankshaft condition, block cracks, cylinder-head corrosion, valve-seat condition, oil-pump wear, and water-distribution hardware can turn an apparently complete engine into an expensive project.

Gearboxes and rear axles are robust but not immune to water-contaminated lubricant, worn bearings, chipped teeth, and tired synchronizers. Column-shift linkage deserves separate attention because accumulated wear can be mistaken for internal gearbox failure. Clutch chatter can come from contamination, weak mounts, flywheel condition, or driveline alignment.

Structural work is often the greater challenge. Check the lower cowl, rocker and sill areas, floors, trunk pan, rear body mounts, fender attachment points, and the structure around the convertible top and door apertures. A body restored off the frame without proper bracing may return with door gaps that cannot be corrected through hinge adjustment.

Routine ownership should include frequent chassis lubrication, brake inspection, cooling-system checks, and attention to fuel and ignition components. Service intervals should follow the appropriate factory manual rather than modern assumptions. Cars driven infrequently benefit from regular heat cycles and road use, provided the braking, tires, steering, and cooling systems are already safe.

Mechanical service items can often be rebuilt or sourced through Cadillac and LaSalle specialists. Convertible-specific trim, top hardware, garnish moldings, grilles, and one-year decorative pieces are much harder to replace. Reproduction availability is selective, which makes a complete but worn car preferable to a freshly painted shell missing irreplaceable fittings.

Buyer and Inspection Points

A serious inspection must establish identity and structural integrity before considering paint gloss or upholstery quality. The following checks target the failures and substitutions most likely to alter the cost or authenticity of a late LaSalle Convertible Coupe.

A pre-purchase inspection should involve both a marque specialist and a body restorer familiar with open prewar cars. A smooth-running engine cannot offset a weakened convertible body, while cosmetic deterioration on a structurally honest and complete car may be comparatively straightforward to correct.

Collector and Market Relevance

Open bodywork, Cadillac V8 power, and final-era status drive demand for the 1937 through 1940 Convertible Coupe. Buyers generally favor cars with a traceable identity, correct Fisher body style, complete trim, original major components, and restoration work supported by photographs and invoices.

Terminal-year 1940 cars attract collectors who want the last LaSalle, while the 1937 model marks the return to Cadillac V8 power. Series 52 examples add the torpedo-body treatment and a distinct body code, but condition, authenticity, and completeness usually outweigh a simple preference for one series.

Auction descriptions often emphasize rarity without separating model-year totals from body-style production. That language should be treated cautiously unless supported by factory records or a recognized marque archive. The real scarcity is visible in the survival of complete, correctly identified open cars with their original trim and unaltered structure.

Cultural Relevance and Club Support

The Convertible Coupe was not a competition special, and attaching a racing narrative to it distorts its purpose. Its cultural value comes from the American luxury market’s prewar companion-marque system, GM styling practice, and the brief period when LaSalle carried Cadillac V8 engineering immediately below Cadillac-branded models.

LaSalle ownership remains closely connected to Cadillac and LaSalle marque clubs, concours events, touring groups, specialist vendors, and technical archives. Club judging has also raised the standard of restoration by documenting year-specific hardware, trim, paint, upholstery, and engine-compartment finishes that were once treated casually.

The model’s visual vocabulary appears throughout late-1930s American popular culture: a long hood, close-coupled open cabin, narrow grille, running boards, and a rear deck sized for touring luggage. Its appeal is strongest when those proportions remain intact, without oversized tires, modern upholstery patterns, or excessive chrome added during restoration.

Frequently Asked Questions

What engine does the 1937–1940 LaSalle Convertible Coupe use?

It uses Cadillac’s 322-cubic-inch, 90-degree L-head V8. Factory output was 125 bhp from 1937 through 1939 and 130 bhp for 1940.

What is the difference between a LaSalle Series 50 and Series 52 Convertible Coupe?

Series 50 was offered throughout 1937 through 1940. Series 52 appeared for 1940 with the newer torpedo-style body treatment and is generally identified as Fisher body style 5267, compared with 5067 for the Series 50 Convertible Coupe.

How can a genuine LaSalle Convertible Coupe be identified?

Check the vehicle serial information, engine number, frame evidence, title, and Fisher Body data plate together. The body tag should carry the correct convertible-coupe style designation for its series and year; no single plate should be accepted without corroborating evidence.

Did the late LaSalle Convertible Coupe have a floor or column shifter?

The 1937 model used a floor-mounted gear lever. LaSalle introduced its steering-column Safety Shift for 1938, and the column arrangement continued through 1940.

What are the most serious restoration problems?

Structural corrosion in the floors, sills, lower cowl, trunk, and body-mount areas can undermine door alignment and body rigidity. Missing convertible-top hardware, damaged grille components, incorrect trim, and a neglected 322 V8 can also make restoration disproportionately expensive.

Are mechanical parts available for the Cadillac 322 V8?

Many service items can be rebuilt or obtained through prewar Cadillac and LaSalle specialists, but availability is not comparable with a postwar mass-production engine. Internal engine work requires knowledgeable suppliers and a machine shop experienced with prewar side-valve construction.

What makes the 1937–1940 LaSalle Convertible Coupe collectible?

It combines an open Fisher body with Cadillac’s 322 V8 and comes from the final four years of the LaSalle marque. Collectors particularly value correct body identity, complete model-specific trim, sound structure, documented restoration work, and an engine consistent with the car’s production period.

Collector Takeaway

The late LaSalle Convertible Coupe deserves attention for two precise reasons. The 1937 model restored Cadillac V8 power to LaSalle, and the 1940 model closed the marque’s 14-year production run. Between those points, the car documented four seasons of rapid change in GM body design without abandoning the durable 322-cubic-inch side-valve engine beneath the hood.

Buy the body, identity, and missing trim before buying the paint. A structurally sound 5067 or 5267 with coherent numbers and complete convertible hardware preserves something difficult to reconstruct: an open LaSalle that is still recognizably the car Fisher and Cadillac built. That combination, not an unsupported production claim or an immaculate modern finish, is what gives the final-era Convertible Coupe lasting collector weight.