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Muscle car

1968 Plymouth Road Runner 383

Muscle car powered by Chrysler 383 four-barrel B-series V8.

1968 Plymouth Road Runner 383 front three-quarter view showing the grille, hood inserts, coupe profile, and model trim
Engine 383 four-barrel B-series V8
Factory rating 335 hp and 425 lb-ft
Body styles Two-door coupe and hardtop
Reported production 44,599 Road Runners; 43,580 standard-engine cars derived

Story

1968 Plymouth Road Runner 383

Plymouth built the first Road Runner around a simple idea: put serious big-block performance in a stripped-down intermediate and keep the price within reach. The standard 383 four-barrel was rated at 335 horsepower and 425 lb-ft, with a special high-lift camshaft, dual exhaust, and the Road Runner's distinctive voice and cartoon identification.

Buyers could choose the pillared two-door coupe or the later hardtop. A three-speed manual, four-speed manual, and TorqueFlite automatic were available with the 383. Heavy-duty torsion bars, rear leaf springs, shocks, and drum brakes were part of the package; the factory data book specifies 11 x 3-inch front and 11 x 2.5-inch rear drums for the Road Runner.

The cabin stayed intentionally straightforward, with a bench seat and minimal ornamentation, while the option list allowed a four-speed floor shifter, TorqueFlite, Sure-Grip, power assists, a tachometer, hood treatment, stripes, and other comfort or appearance choices. Twenty-two model-year Plymouth paint colors are listed here, but an individual car's fender tag and records remain the authority for its original finish and trim.

Published references report 44,599 Road Runners for 1968: 29,240 coupes and 15,359 hardtops. With 1,019 reported Hemi cars, 43,580 standard-engine cars is a useful derived figure, not a substitute for an original factory engine report.

Authenticating a 383 Road Runner requires agreement among the VIN, fender tag, broadcast sheet, engine and transmission stampings, axle information, paint, trim, and options. Road Runner emblems, a beep-beep horn, hood treatment, or an installed 383 do not establish how a particular car left the factory.

Price history

Values

Nominal dollars from original price sheets, auction archives, and approved value references.

Original Price

A verified original price is not yet available for this car.

Market Observations

  • Auction sale $15,500

    Jul 17, 2025 · Bring a Trailer

    H-code four-speed hardtop RM23H8G239632 whose fender tag documents factory 383 and four-speed equipment, sold as a running project with a color change, aftermarket carburetor and ignition, traction bars, raised rear suspension, rust holes, and torn upholstery. · modified · project Bring a Trailer records a $15,500 sale and explicitly categorizes the car as a project. The fender tag establishes the factory 383/four-speed configuration, while the repaint, aftermarket equipment, corrosion, body rust, and interior damage support modified build state and project condition.
  • High bid $30,000

    Jan 21, 2024 · Bring a Trailer

    H-code hardtop RM23H8G246641 whose fender tag documents factory 383 and automatic equipment, now with an overbored engine, aftermarket induction and ignition, Hotchkis suspension, larger wheels, color change, and interior changes. · modified · unknown Bring a Trailer records a $30,000 reserve-not-met high bid. The fender tag establishes the factory 383 Road Runner pathway, while the rebuilt overbored engine and substantial appearance, suspension, wheel, audio, and color changes require a modified classification. This is a no-sale signal, not a transaction price.
  • Auction sale $51,700

    Nov 12, 2022 · Mecum Las Vegas

    H-code Road Runner coupe RM21H8G253490 with a comprehensive restoration, 383 V8, automatic transmission, aluminum radiator, power brakes, and Mopar Performance engine dress kit. · restored · unknown Mecum records a $51,700 sale and supplies the H-code VIN, 383 drivetrain, body, restoration, and equipment context. Condition remains unknown because the auction description does not assign a compatible condition grade or document restoration quality in enough detail.

Values move with paperwork, originality, options, condition, venue, and body style. High bids and guide values are labeled separately from completed sales.

Reference records

Options, Colors & Components

Source-backed details for trim, chassis, production, and authenticity.

Engine Details

1968 Plymouth Road Runner with hood open, showing 383 engine-bay contextBull-Doser via Wikimedia Commons · Public domain
  • Engine construction Overhead-valve cast-iron block V8 with five main bearings · 1968 Road Runner 383 CID High Performance 4-barrel V-8 · engine assembly / specification
  • Bore and stroke 4.250 x 3.375 inches · 1968 Road Runner 383 CID High Performance 4-barrel V-8 · engine assembly / specification
  • Compression ratio 10.0:1 · 1968 Road Runner 383 CID High Performance 4-barrel V-8 · engine assembly / specification
  • Horsepower rating 335 @ 5200 RPM · 1968 Road Runner 383 CID High Performance 4-barrel V-8 · engine assembly / specification
  • Torque rating 425 @ 3400 RPM · 1968 Road Runner 383 CID High Performance 4-barrel V-8 · engine assembly / specification
  • Valve lifters Hydraulic · 1968 Road Runner 383 CID High Performance 4-barrel V-8 · valve train / specification
  • Camshaft timing Intake 268 degrees, exhaust 284 degrees, overlap 46 degrees · 1968 Road Runner 383 CID High Performance 4-barrel V-8 · camshaft / specification
  • Camshaft lift 0.450 inch intake, 0.465 inch exhaust · 1968 Road Runner 383 CID High Performance 4-barrel V-8 · camshaft / specification
  • Carter AVS carburetor, manual transmission AVS-4428S · 1968 Road Runner 383 CID High Performance 4-barrel V-8 with manual transmission · carburetor / carburetor list
  • Carter AVS carburetor, automatic transmission AVS-4429S · 1968 Road Runner 383 CID High Performance 4-barrel V-8 with automatic transmission · carburetor / carburetor list
  • Model availability Only available in Road Runner and Super Bee · 1968 383 CID High Performance 4-barrel V-8 · other / specification

Transmission

  • Factory transmission Three-speed manual
  • Factory transmission A833 four-speed manual
  • Factory transmission TorqueFlite three-speed automatic

Options

383 Four-Barrel reference for the 1968 Plymouth Road Runner 383Classic Muscle · Reference illustration

Paint

1968 Plymouth Road Runner rear three-quarter view showing the tail panel, roofline, and body proportionsChristopher Ziemnowicz via Wikimedia Commons · Public domain

Chassis

Authenticity

Factory Brakes reference for the 1968 Plymouth Road Runner 383Classic Muscle · Reference illustration
  • Factory Road Runner identity Original Road Runner model records and trim consistent with the car's body style · VIN, fender tag, broadcast sheet, original invoice, and body details · fraud detection
  • Original 383 drivetrain Car-correct 383, transmission, and axle dates and identifiers that agree with factory records · Engine pad and casting date, transmission stamping, axle tag or stamping, fender tag, and broadcast sheet · numbers matching
  • Original paint and interior Paint and trim that agree with the fender tag and surviving factory paperwork · Fender tag, broadcast sheet, hidden original paint, upholstery details, and restoration records · trim correctness

Still Researching

  • engine Core 383 specifications, camshaft timing/lift, and Carter AVS carburetor applications are recorded, but complete casting, assembly, part-number, and date-code tables are not.
  • transmission All three transmission paths are recorded, but complete sales codes, application numbers, and production windows are not.
  • rear axle Heavy-duty axle and Sure-Grip context is recorded, and standard 3.23:1 plus optional 3.55:1 Road Runner 383 high-performance rear-gear ratios are now source-recorded; assembly codes, date windows, and car-specific axle documentation remain incomplete.
  • brakes Road Runner drum dimensions and power/disc options are recorded, but part numbers and all ordering restrictions are not.
  • suspension Factory layout, front torsion-bar dimensions, and shock design are documented, but rear-spring and remaining shock/stabilizer part applications remain unresolved.
  • option packages Major performance and appearance choices are recorded, but the complete ordering and incompatibility matrix is not.
  • production Body totals and a derived 383 figure are recorded, but a factory engine/transmission production report is not attached.
  • paint colors The model-year Plymouth palette is recorded, but Road Runner restrictions and color-frequency records are not.
  • trim and appearance Road Runner identifiers and appearance choices are recorded, but every sales-code combination and part number is not.
  • interior Seat, shifter, tachometer, and basic trim context is recorded, but the complete upholstery code matrix is not.
  • authenticity markers Document and component checks are recorded, but exact decoding, casting, and acceptable date-window guidance is incomplete.

Codes & names

Names & Engine Codes

Common names and codes are grouped so LS6 references point to the same engine, not separate pages.

Heavy-Duty Chassis reference for the 1968 Plymouth Road Runner 383Classic Muscle · Reference illustration
383 4-BBL. V8 Chrysler 383 four-barrel B-series V8
383 Road Runner Chrysler 383 four-barrel B-series V8
Road Runner 383 Chrysler 383 four-barrel B-series V8
383 CID 4-Barrel V-8 Chrysler 383 four-barrel B-series V8
383/335 HP Chrysler 383 four-barrel B-series V8

Photo and video gallery

Gallery

5 photos and videos

Sources & Documentation

Reader contributions

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