LS3-Powered 1940 Buick Series 50 Super Convertible

Description

Introduced toward the culmination of the Art Deco era, Buick’s 1940 Series 50 blended curvaceous coachwork with polished road manners, positioning it as a stylish yet attainable luxury General Motors offering. With its long hood and sweeping fenders, the Series 50 has long appealed to customizers for its modern performance adaptability while retaining its classic Art Deco character.

This LS3‑powered 1940 Buick Series 50 Super Convertible was customized by previous owner in 2014, reportedly at a cost exceeding $100,000. The original frame and suspension were replaced with a Lator Gator USA custom chassis featuring a C4 Corvette-based independent suspension, power rack‑and‑pinion steering, and disc brakes at all four corners. Adjustable Strange Engineering coilovers are fitted, and the car rides on 16-inch Dayton knock‑off wire wheels wrapped in BFGoodrich whitewall tires.

Power is provided by a GM Performance 6.2‑liter LS3 V8 paired with a GM 4L65E automatic transmission, all managed by a GM Performance ECU. Supporting modifications include stainless‑steel fuel lines, an electric fuel pump, and a stainless‑steel exhaust system with MagnaFlow mufflers. Inside, the cabin features two‑tone diamond‑stitched upholstery, a color‑matched dashboard, New Vintage USA Woodward gauges, Vintage Air climate control, and an Alpine head unit. Before the seller acquired this modified Buick in 2025, a prior owner replaced its tires, accessory belt, fluids, and brake lines.

This modified 1940 Buick Series 50 Super Convertible is now offered with a spreadsheet detailing its modifications and a clean Illinois title in the seller’s name.

Highlights

• Powered by a GM Performance 6.2‑liter LS3 V8

• GM Performance 4L65E automatic transmission

• Lator Gator USA chassis utilizing C4 Corvette-based suspension

• Custom two‑tone, diamond‑stitched distressed tan interior

• Vintage Air climate control

Modifications

The following modifications were performed prior to the seller's acquisition. A spreadsheet detailing the modifications can be found under "Additional information" below.

• Powertrain & Drivetrain:

  • GM Performance 6.2‑liter LS3 crate engine

  • GM Performance ECU and engine module kit

  • GM Performance 4L65E automatic transmission

  • Stainless‑steel fuel lines and electric fuel pump

  • Updated accessory belt and fluids

  • Stainless‑steel exhaust system

  • MagnaFlow mufflers

• Chassis & Suspension:

  • C4 Corvette-based independent suspension

  • Adjustable Strange Engineering coilovers

  • Lator Gator USA full custom chassis

  • Power rack‑and‑pinion steering

  • Disc brakes at all four corners

  • Hydratech Hydroboost braking system

  • Chrome dual‑reservoir master cylinder

  • Russell Performance braided front brake hoses

• Exterior:

  • Power‑operated dark red convertible top

  • LED headlights and exterior lighting

  • Shaved door handles with popper kit

  • Key‑fob‑operated doors and trunk

  • 16″ Dayton knock‑off wire wheels wearing BFGoodrich whitewall tires

• Interior:

  • Door‑mounted speakers and trunk‑mounted subwoofer

  • Custom two‑tone distressed tan interior upholstery

  • Diamond‑stitched front and rear bench seats

  • Alpine head unit with USB and Sirius connectivity

  • Bound carpeting with Dynamat insulation

  • One‑off ignition dial with push‑button start

  • Color‑matched custom dashboard

  • Vintage Woodward gauges

  • Vintage Air climate control

  • Grant steering wheel

Servicing & Documentation

The following work was reportedly performed prior to the seller's acquisition in 2025:

• Russell Performance braided front brake hoses installed

• Accessory belt and fluids changed in preparation for sale

• Replacement BFGoodrich whitewall tires

Known Imperfections

• Paint chips and cosmetic imperfections consistent with age

• Chrome shows pitting in areas

• Blemish present on hood

Ownership History

The Series 50 Super Convertible was modified under previous ownership beginning in 2014, at which time it underwent a documented custom build with an investment exceeding $100,000.

Included

• Build spreadsheet