Rare Car Archive

Makes › Ford United States › Mustang › First generation › Mustang (1969–1970) › Mustang Boss 429 · Rare factory specification Rare

Ford Mustang Boss 429

Every Boss 429 was built by hand at Kar Kraft’s facility in Brighton, Michigan, and carries a Kar Kraft (“KK”) number starting at KK NASCAR 1201. 1969 cars had a hydraulic-lifter camshaft, 1970 cars a mechanical one. The base price is given as $4,087; Sports Car Market quotes a list price of $4,900 for a 1970 car.

1,358Built 1969–70Independently researched
299,8241969 Mustangs builtWhole model, for context
4Chassis documentedin this archive
Contents
  1. 01Overview
  2. 02Production & history
  3. 03Specifications
  4. 04Colours & options
  5. 05Individual cars
  6. 06Reference

01Overview

What exactly is rare

Mustangs built by Kar Kraft with the 429 cu in “Boss” V8, created to homologate the engine for NASCAR – 1,358 cars in 1969–1970, against nearly half a million Mustangs built in those two years.

At a glance

Built
1,358 Built 1969–70
Years
1969–1970
Engine
Ford 429 “Boss” V8 (NASCAR homologation engine) · 7,030 cc / 7.0 LFactory: 429 cu in · converted
Power
280 kW / 380 PSFactory: 375 hp · converted
Top speed
190 km/hFactory: 118 mph · converted
Body
Not yet verified
Designer
Not yet verified
Surviving
Not yet verified

Sources and any conflicting figures are in the sections below.

Why it matters

The Boss 429 existed to make Ford's new semi-hemispherical 429 cu in V8 legal for NASCAR, whose rules required the engine to be sold in at least 500 road cars. Fitting the large engine into the Mustang required hand modification of each car at Kar Kraft, making it one of the most heavily reworked production Mustangs of its era. The engine went on to race in NASCAR until 1974 in other Ford and Mercury bodies.

How rare is it?

Specification rarity is not model rarity.

Model rarityNot yet assessed
Specification rarityRare 1,358 · Built 1969–701,2
Colour rarityNot yet assessed
Individual rarityNot yet assessed
Historical rarityNot yet assessed
Survival rarityNot yet assessed

Each kind of rarity is rated separately and never combined.

02Production & history

Production

Figures for this configuration only.

What is countedFigureBasisStatus
Factory package production1970 Boss 429 4991,3,4Strongest evidence Factory production Independently researched
Factory package productionAll Boss 429 Mustangs, 1969–1970 1,3581,2Strongest evidence Factory production Independently researched
Factory package production1969 Boss 429 Mustangs only 8573 Factory production Independently researched
Factory package production1969 Boss 429, including two Boss 429 Cougars 8591,5,4 Factory production Independently researched
Factory package production1970 Boss 429 including two “Quarter Horse” prototypes 5005,6 Factory production Independently researched
Why more than one figure?

Some sources count 500 by including two “Quarter Horse” prototypes; others give 499.

Independent counts (e.g. engine and colour) are never combined into a calculated figure. Surviving examples are never presented as original production.

Model production: Mustang (1969–1970)

Shown for context. These figures count the whole model, not this specification.

What is countedFigureBasisStatus
Model-year production1969 model year, all Mustangs 299,8247 Factory production Independently researched
Model-year production1970 model year, all Mustangs 190,7278 Factory production Independently researched

Independent counts (e.g. engine and colour) are never combined into a calculated figure. Surviving examples are never presented as original production.

History

Facing Chrysler's 426 Hemi in NASCAR, Ford developed a racing version of its new 385-series big-block with aluminium heads using a semi-hemispherical ("crescent") combustion chamber. To homologate it, Ford had to offer the engine to the public in a road car, and chose the Mustang SportsRoof.

Because the engine did not fit the standard car, Ford sent Mustangs to Kar Kraft in Brighton, Michigan, where the front shock towers were cut and relocated, the battery moved to the trunk and a driver-controlled hood scoop fitted. Each car received a Kar Kraft number, from KK 1201 onwards. 1969 engines used hydraulic lifters; 1970 engines switched to a mechanical camshaft.

RM Sotheby's gives production as 859 for 1969 (including two Boss Cougars) and 500 for 1970 (including two "Quarter Horse" prototypes); other sources give 499 for 1970.

03Specifications

Technical specifications

Values for this specification. See the model page for the base car.

Engine

Engine familyFord 385 series9,10 Independently researchedFord's 1969 sales sheet markets the engine as the "429-CID Cobra Jet HO".
Engine codeNot yet verified
LayoutFord 429 “Boss” V8 (NASCAR homologation engine)11,5 Independently researched
Displacement 7,030 cc / 7.0 LFactory: 429 cu in · converted5 Independently researched
Bore 111 mmFactory: 4.36 in · converted12,13
Stroke 91.2 mmFactory: 3.59 in · converted12,13
Compression ratio10.5 : 1 or 11.0 : 1 (sources differ)5,14 Disputed
Fuel systemHolley 735 cfm four-barrel carburettor5,14 Independently researched
Power 280 kW / 380 PSFactory: 375 hp · converted14,5,12Rating: SAE gross
Power at 5,200 rpm6 Independently researched
Torque 556 NmFactory: 410 lb-ft · converted12Also reported: 450 lb-ft6 Discrepancy
Torque at 3,400 rpm12

Transmission & drivetrain

GearboxFord “Top Loader” close-ratio four-speed manual5 Independently researched
Gears45 Independently researched
Final drive3.91 : 1 Traction-Lok14,5 Independently researched
Driven wheelsrear12,15

Chassis, body & dimensions

ChassisSteel platform chassis (Mustang unit structure with relocated front shock towers)12,15
Front suspensionIndependent, upper and lower A-arms, heavy-duty coil springs, stabilizer bar12,15
Rear suspensionLive axle on heavy-duty semi-elliptic leaf springs, stabilizer bar, staggered shock absorbers12,15
BrakesPower-assisted floating-caliper front discs (11.3 in), rear drums (10 x 2 in)12
SteeringPower steering with power-steering oil cooler12,16
Body constructionSteel two-door SportsRoof (fastback) body12
Wheelbase 2,740 mmFactory: 108 in · converted12,15
Length 4,753.4 mmFactory: 187.14 in · converted12
Width 1,830 mmFactory: 71.9 in · converted12
Height 1,300 mmFactory: 51.2 in · converted12
Front track 1,510 mmFactory: 59.3 in · converted12
Rear track 1,490 mmFactory: 58.5 in · converted12
Kerb weight 1,686 kgFactory: 3,716 lb · converted121969 sales sheet. Car Life (7/69, via The Auto Channel) lists 3,870 (test weight, unit not stated); mustangspecs.com gives 3560 lbs for the 1970 car.
Dry weightNot yet verified

Performance

Maximum speed 190 km/hFactory: 118 mph · converted17 Independently researchedRoad-test figure from Car Life, July 1969, quoted secondhand by The Auto Channel; the original magazine was not consulted. Same test: 0-60 mph 7.1 s, quarter mile 14.09 s @ 102.85 mph.
0–100 km/hNot yet verified
0–60 mph 7.1 s17 Independently researchedmustangspecs.com quotes 5.1 s for a 1970 car without naming a test.
Fuel tankNot yet verified

“Not yet verified” means no source has been checked for that value yet. Nothing is estimated to fill a gap.

04Colours & options

Factory colours & interiors

CodeExteriorInteriorCars
— Grabber Green1 — 521,18
— Pastel Blue19 — 1819

1970 Boss 429; single source, not checked against a registry

Factory options & codes

Codes are shown exactly as written by the manufacturer.

Not yet documented. Have a source? Contribute it.

05Individual cars

Chassis register

Every documented car, with its colours, history and where it is now. Open a row for the full record. Known chassis are not automatically authenticated originals.

ChassisBuiltOriginal colourWhere nowStatus
9F02Z159757—Raven BlackPrivate collectionHistorically documented

Ford Mustang Boss 429 KK 1356

1969 car stored in a barn for 30 years; its original engine was removed in the late 1980s and never recovered.

VIN
9F02Z159757
Original exterior
Raven Black20 Independently researched
Where now
Private collection
  1. 1969-02-21
    Factory Built; delivered through Hill & Sanders Ford, Wheaton, Maryland.20
  2. 2021-03
    Auction Sold at RM Sotheby’s Open Roads, lot 261. 181,500 USD20
20
9F02Z198892—Candyapple RedPrivate collectionHistorically documented

Ford Mustang Boss 429 KK 2029

VIN
9F02Z198892
Original exterior
Candyapple Red11 Independently researched
Original interior
Black knit vinyl11 Independently researched
Where now
Private collection
  1. 1969-08-25
    Delivery Sold new by Nelson Ford Company, Broken Arrow, Oklahoma.11
  2. 2016-06
    Auction Sold at RM Sotheby’s Santa Monica, lot 1098. 220,000 USD11
11
0F02Z123173——Private collectionHistorically documented

Ford Mustang Boss 429 KK 2290

VIN
0F02Z123173
Where now
Private collection
  1. 2012-01
    Auction Sold at RM Sotheby’s Arizona, lot 228; four documented owners. 170,500 USD5
5
0F02Z140991—Grabber GreenPrivate collectionHistorically documented

Ford Mustang Boss 429 KK 2446

VIN
0F02Z140991
Original exterior
Grabber Green1 Independently researched
Original interior
Black knit vinyl1 Independently researched
Where now
Private collection
  1. 1969-12-01
    Factory Built; delivered to Minar Ford, Minneapolis. Drag Pack.1
  2. 2023-01
    Auction Sold at RM Sotheby’s Arizona, lot 114. 280,000 USD1
1

Competition history

Not yet documented. Have a source? Contribute it.

Auction & sale history

DateChassisEvent
2012-010F02Z123173Sold at RM Sotheby’s Arizona, lot 228; four documented owners. 170,500 USD5
2016-069F02Z198892Sold at RM Sotheby’s Santa Monica, lot 1098. 220,000 USD11
2021-039F02Z159757Sold at RM Sotheby’s Open Roads, lot 261. 181,500 USD20
2023-010F02Z140991Sold at RM Sotheby’s Arizona, lot 114. 280,000 USD1

06Reference

Identification guide

How to tell an original from a replica or later conversion.

1969 colours: Wimbledon White, Royal Maroon, Raven Black, Black Jade, Candy Apple Red. 1970 colours: Grabber Blue, Grabber Green, Grabber Orange, Calypso Coral, Pastel Blue. The engine tag changed from 820-S to 820-T when the connecting-rod bolts were changed.

Sources

Each number links to the exact facts it supports.

  1. 1
    1970 Ford Mustang Boss 429, Arizona 2023, lot 114 Level C RM Sotheby’s
    • “One of 1,358 produced in total”
    • including 499 1970 models
    • “Just 859 were made in 1969”
    • Grabber Green
    • “One of 52 1970 Boss 429s produced in … Grabber Green”
    • black knit vinyl
    • Built 1 Dec 1969, Minar Ford
    • $280,000 sold
    • KK 2446, VIN 0F02Z140991
    Accessed 2026-11-11
  2. 2
    Ultimate Ford 429 engine guide Level C Austin Parsons · Muscle Car Club · 2024-02-20
    • 1,358 Boss 429 engines, all in the Mustang
    Accessed 2026-11-11
  3. 3
    1970 Ford Mustang Boss 429 (profile) Level C Colin Comer · Sports Car Market · 2010-10-28
    • 499 in 1970
    • Number produced: 857 in 1969
    Accessed 2026-11-11
  4. 4
    1969–70 Boss 429 Mustang – Auto Channel looks back Level C The Auto Channel · 2023-01-11
    • 499 in 1970
    • Includes 2 Boss 429 Cougars
    Accessed 2026-11-11
  5. 5
    1970 Ford Mustang Boss 429, Arizona 2012, lot 228 Level C RM Sotheby’s
    • 859 (including two Boss-Cougars)
    • Just 500 more followed for 1970 (including two “Quarter Horse”)
    • 375 bhp, 429 cu. in. Boss V-8 engine
    • 429 cu. in.
    • 10.5:1
    • Holley 735 cfm four-barrel carburetor
    • 375 bhp
    • Ford “Toploader” close-ratio four-speed manual transmission
    • four-speed
    • nine-inch Traction-Lok with 3.91:1 gears
    • $170,500 sold
    • KK 2290, VIN 0F02Z123173
    Accessed 2026-11-11
  6. 6
    1970 Ford Mustang Boss 429 Level C MustangSpecs
    • 500 including two Quarter-Horse Mustangs
    • 375 HP @ 5,200 RPM
    • 450 lb-ft of torque
    Accessed 2026-11-11
  7. 7
    1969 Ford Mustang production numbers Level C MustangSpecs
    • “A total of 299,824 Mustangs were sold in 1969.”
    Accessed 2026-11-11
  8. 8
    1970 Ford Mustang production numbers Level C MustangSpecs
    • “A total of 190,727 Mustangs were sold in 1970.”
    Accessed 2026-11-11
  9. 9
    Car of the Week: 1970 Ford Mustang Boss 429 Level C Al Rogers · Old Cars Weekly · 2025-08-18
    • its newest engine family, the Ford 385
    Accessed 2026-11-11
  10. 10
    Secrets of the Ford Boss 429 V8 Level D Mac's Motor City Garage · 2020-07-09
    • the 385 series, also known as the Lima V8
    Accessed 2026-11-11
  11. 11
    1969 Ford Mustang Boss 429, Santa Monica 2016, lot 1098 Level C RM Sotheby’s
    • KK 429 NASCAR production number
    • Candyapple Red
    • black Clarion knit/vinyl
    • sold new on August 25, 1969 at Nelson Ford
    • $220,000 sold
    • KK 2029, VIN 9F02Z198892
    Accessed 2026-11-11
  12. 12
    Boss 429 – The "Take Charge" Mustang from Ford (1969 dealer sales sheet) Level A Ford Division, Ford Motor Company (scan hosted by ponynsnake.com)
    • Bore 4.36 Inches (Engine specifications)
    • Stroke 3.59 Inches (Engine specifications)
    • Brake Horsepower ....375 (Page 4, Engine block)
    • Torque @ 3400 RPM (lbs./ft.) ....410 (Page 4, Specifications and Engine blocks)
    • Torque ....410 @ 3400 (Page 4, Engine block)
    • Rear Axle... Hypoid... Traction-Lok Differential
    • Construction: Steel, Platform Chassis (Specifications)
    • ultra-heavy-duty front coil... front and rear stabilizer bars
    • rear leaf springs... staggered rear shock absorber arrangement
    • Power Assist Floating Caliper Front Disc... Rear Drums (Brakes)
    • Front Disc Diameter 11.3 Inches; Rear 10x2 Inches
    • Power steering with special power steering oil cooler
    • BOSS 429 Mustang SportsRoof model; Construction Steel
    • Wheelbase 108 (Dimensions)
    • Overall Length 187.14 (Dimensions)
    • Overall Width 71.9 (Dimensions)
    • Overall Height 51.2 (Dimensions)
    • Tread Front 59.3 (Dimensions)
    • Tread Rear 58.5 (Dimensions)
    • Curb Weight (lbs.) 3716 (Specifications)
    Accessed 2026-11-11
  13. 13
    4/29: It's Boss 429 day – celebrate Ford's big-bore semi-hemi engine Level C David Kennedy · NHRA · 2025-04-29
    • 4.36-inch bore with the 460
    • shorter 3.59-inch stroke
    Accessed 2026-11-11
  14. 14
    1970 Ford Mustang Boss 429, Amelia Island 2020, lot 280 Level C RM Sotheby’s
    • 11.0:1
    • 735 CFM Holley
    • “conservatively rated at 375 horsepower”
    • 3.91:1 Traction-Lok rear axle
    Accessed 2026-11-11
  15. 15
    1970 Ford Mustang Boss 429 (KK2290), Arizona 2012 lot 131 Level C RM Sotheby's
    • live Traction-Lok rear axle
    • cutting and relocation of the front shock towers
    • coil springs, upper and lower A-arms and stabilizer bar
    • semi-elliptic leaf springs, stabilizer bar and staggered shock absorbers
    • Wheelbase: 108"
    Accessed 2026-11-11
  16. 16
    1969 Ford Mustang Boss 429 (KK 2029), lot 124 Level C RM Sotheby's
    • Marti equipment list includes power steering (paraphrase)
    Accessed 2026-11-11
  17. 17
    1969-70 Boss 429 Mustang – The Auto Channel looks back Level C The Auto Channel · 2023-01-11
    • Top speed 118 mph (Source: Car Life 7/69)
    • 0-60 mph 7.1 (Source: Car Life 7/69)
    Accessed 2026-11-11
  18. 18
    RM Sotheby's Arizona 2023 – 1970 Ford Mustang Boss 429 Level B
    • 52 1970 Boss 429s in Grabber Green (of 499)
    Accessed 2026-11-12
  19. 19
    RM Sotheby's Arizona 2012 – 1970 Ford Mustang Boss 429 Level B
    • 18 Boss 429s painted Pastel Blue
    Accessed 2026-11-12
  20. 20
    1969 Ford Mustang Boss 429, Open Roads, lot 261 Level C RM Sotheby’s
    • Raven Black over black
    • Built 21 Feb 1969
    • $181,500 sold
    • KK 1356, VIN 9F02Z159757
    Accessed 2026-11-11

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