You are a fan of Ford Mustang and considering the Boss series in the 1969- 1971 period?

As you know, Boss 429 was introduced in 1969. Its primary purpose was to endorse the Hemi-headed engine for the NASCAR competition. This car is for prominent persons, is unique among other Mustangs, and is the strongest Boss of the period.

On the other hand, the Boss 302’s dominion lasted for one year besides its renowned sibling, the Boss 429. It was produced for the Trans Am competition series.

The 1971 Boss 351 was a substitute for the Boss 302, and Knudsen and Shinoda determined its arrival in the market. Its name originates from the replacement of its engine from Cleveland V-8.

To make decision which one is worth buying, we should take a look at their main features and what they can do.

Feature Overview

Boss 429

Boss 351
Image source: wikipedia

Boss 429 has an engine capacity of 428.8-cu-in/7027cc. It also has a 4-speed manual transmission with front solid disc brakes at the front part. The model has control arms, coil springs, and an anti-roll bar at the front and a live axle and leaf springs at the back. It is 3400 lb in weight and has a speed limit of 60 mph within 5 minutes and 3 seconds per quarter-mile. The Boss 429 battery was shifted to the trunk, and the assemblers included a three-quarter sway bar was in the back end to enhance the car’s operation. The technicians fixed it with an AM radio and an 8,000 rpm tachometer.

Boss 302

Boss 302
Image source: wikipedia

Boss 302 has an engine capacity of 301.6-cu-in/4942cc. The car has a 4-speed physical transmission accompanied by solid disc brakes at the front and drum brakes at the rear part. The rear part has control arms, coil springs, and an anti-roll bar, while the rear part has a live axle and leaf springs. It weighs 3,300 lb and has a speed limit of 60 mph within 8 minutes 1 second per quarter-mile. The Boss 302 was reproduced with forged models containing hot wheels and a matchbox. It is observable by the hockey stick sideline and rear airshafts.

Boss 351

Boss 351
Image source: wikipedia

The engine capacity of Boss 351 is 351.9-cu-in/5766cc. It has a 4-speed manual drive train and solid disc brakes at the fore and drum brakes at the back. The car has 3,452 lb of weight and borrowed the Ram Air hood scoop and spoiler of its exterior design from March 1 . The Boss 351 came in different colors of Grabber Lime and Medium Yellow Gold, Calypso Coral’s unique color.

Pros & Cons Comparison Table

Boss 351Boss 351 has a higher compression and rise in displacement, which means it is best modified to utilize the port volume and the final flow potential.
It also has a high igniting block engine with deeper breathing due to big ports and pipes in the cylinder heads; hence it is faster.
The 351 had wheel hop due to its wheels moving more easily than they should, leading to their failure to contact the ground.
On the other hand, its spare parts’ price is slightly higher and is difficult to find.
Boss 429Boss 429 has an excellent ground-up restoration.
The model also has a perfect and highly elaborate engine bay with accurate emissions-control tools in place. It had magnum wheels with F60 wide oval tires, which enabled greater clear focus for the driver.
It also overshadowed the 1969 NASCAR period, getting an enormous 26 wins in the year.
The cost of producing the Boss 429 was high. There was also a drop in sales in 1970 due to high gas costs and other internal Ford problems. The car also had assembly problems like large holes in the firewall, which did not properly contain fuel battery cables.
Boss 302The engine’s sound is great with an identifiable exhaust system. Besides, the 6-manual transmission is easy to change without difficulty. It also has three feedback adjustments (sport, normal, and comfort). The adjustments have balance management systems that give various engagement modes when driving, such as full or intermediate sport mode.The idea of using this particular car that is only suitable for drivers who can drive manually is a challenge. Moreover, the fog lights on the grill are locked up, making them resemble forged plastics. Drivers of the Boss 302 are easily noticed by the police, which makes them feel uneasy.

Engine Specification Comparison

302 engine was manufactured in 1968 for the Trans-Am road competition event. The broad and huge port heads with unsteady valve positioning give the 302 H.O great power potentiality. Due to the heads’ pent-roof arrangement, the Boss had forged emerging pistons to attain the suitable 10.5:1 compression ratio. Fuel was supplied by a Holley 780 cu ft/min physical choke carburetor. The power generation was 290 hp (216 kW) at 5,200 RPM with the highest torque of 290 lb. ft (393 N.m) at 4300 RPM,and a 6,250 RPM limit.

The Boss 351 engine started in 1969 with a 351 cu in (5.8L) engine, generally known as 351C. The engine contained cast-aluminum horizontal top pistons with an 11.0:1 compression ratio at 300 bhp (224kW; 304 PS) at 5400 revolutions per minute. It also needed premium fuel, which was accessible in 1970-1971 Mercury Montego and Ford Mustang.

The Boss 429 engine was produced in 1969-1970 with 375 bhp at 5200 rpm and 450lb of torque at 3400rpm. The engine was ordinary, with one Holley-4barrel carburetor estimated at 735 CFM attached on an aluminum inlet.

Cylinder borePiston strokeValvetrainCompression ratioDisplacementPower outputTorque outputSpecific powerFuel System/Type
Boss 3514.0 in (102mm)3.5 in (89 mm)Overhead valve. Cast iron cam,flat tappet11.0:1351 in3(5.8L)300bhp(224kW;304PS)@5,400 rpm380lb@3,400rpm246 hp (183 kW)Carburetor/premium gas
Boss 4294 in (36mm)3 in (59 mm)10.5:1429CU in(7.0 L)375hp@5,200
450lb@3,400 RPM375 hp (280 kW)Holley Carburetor
Boss 3024 in (101.6mm)3 in (76.2 mm)OHV 2 valves x cyl.10.5:1302 cu in (4.9 L)290 hp (216 kW) @ 5200 rpm290 lb⋅ft (393 N⋅m) @ 4300 rpm59.2 hp (44.1 kW)/LiterHolley Carburetor/Gasoline

Exterior Comparison

Boss 351

Considering the points raised in this article, I concur that the color range for the Boss 351 contained blue, black, red, ginger, green, and white. The Boss 351 registry indicated that seven among ten cars had black interiors. Its labels are at the lower front mudguards and the rear dashboard. Most of the bonnet is painted black or silver depending on the body color and has a wide line down the center.

Boss 429

The Boss 429 had five exterior colors (green, red, orange, blue, and calypso coral. They had a manual transmission and never had an air conditioner because of the engine size. The completely functional hood scoop was bigger than any car part and had the same color. The Boss 429 has Magnum 500 wheels with large oval tires. The car’s bulging rear lights were hollowed, mechanics modified hood pins were into fasteners, and completely removed the back quarter panel.

Boss 302

ColorLenghtWeightHeightWheel base
Boss 351Black, white, ginger, green, red, blue189.5inches/4,813mm3,560lb/1615kg50.1 inches/1273mm109.0 inches/2769 mm
Boss 429Green, red, orange, blue, calypso coral187.4inches/4,760mm3,870lb/1,755kg50.4 inches/1280mm108 inches/2740 mm
Boss 302Orange, dark aqua, yellow, medium lime188.1inches/4,788mm3,631lb/1,647kg55.1inches/1,400mm107.1inches/2720mm

Interior Comparison

The Boss 429 has a manual program with no air conditioner because of the engine size. It had magnesium outlet covers with no smoke emission tools. Its interior was available in black or a mixture of black and white.

The Boss 302 has black leather with orange insets with a dashboard signed by Steve Saleen and Parnelli Jones. The car is smooth and cozy and performs like it is on rails. The brake system has a specific Saleen 4-piston front and open propellers. The interior also included bucket seats, wooden piece dashboard, door fringe, and gearshift knob accents. More options involved the option of a middle console, inclined steering wheel, and different radio alternatives. The bottom interior presented the Mustang’s standard gauge setting, which constituted temperature, alternator, oil pressure indicator, and fuel.

The Boss 351 presented a high-back bucket seat and coolant heat gauges fixed on a panel over the radio. It has comfortable knitted inserts and a fancy March 1 sports interior system.

Performance Comparison

The Boss 302 “G” code engine was estimated at 290 hp (216kW), and this car could increase from 0 to 60 mph in 6.9 seconds; the quarter-mile covered 14.6 seconds, attaining a speed of 98 mph. The car had a live rear axle instead of an independent back suspension to enhance handling through corners. This model has a combination of torque, light systems, and a jerk action of the fast transmission, making the car easy to drive. The Boss 302 uses a fair amount of steering lock to make a turn into a corner and does not take much effort to generate light.

The Boss 429’s engine depended on the Ford 385 and used forged steel and connecting rods, and it managed to cover 30 mph in 3.2 seconds. The car used dry-deck heads, which indicated that there was no regular head gasket.
The performance between the three cars depends on the contrast between big and small block engines. Even though the Boss 351 had extra displacement and compression than the 302, it was a small block engine, contrary to the bigger 429. Cleveland’s 351-CID engine produced the Boss 351 engine, unlike the Boss 302’s Windsor. The Boss 302 Windsor was manufactured using a Windsor 302-CID engine; however, the engineers incorporated Cleveland’s heads into the block because of their bigger ports and outlets. The extra space enhanced the engine’s breathing.

The Boss 351 used the complete Cleveland engine instead of the heads, which increased its compression ratio compared to the Boss 302. To enhance the Boss 351’s performance, the mechanics improved its pistons to forged aluminum and added four bolts to the block.

Price Comparison

The Boss 302 cost a reasonable price of $40,145. However, with the manufacture of a special version, its value has depreciated, and one can obtain a used one at $20,000. Rosenholtz (2019) explains that any buyer can get a short mileage at the original manufacturer’s suggested retail price. Therefore, a budget between $20,000 and $30,000 is affordable. The car’s spare parts are very costly and difficult to obtain; hence, buying a vehicle with scarce original spare parts expensive in the long run.

Therefore, one must do extensive research or consult an expert to advise on the value of the investment before the purchase. The Boss 351’s spare parts are readily available in the market, both in the factory’s new old stock and after-market. This fact makes the car affordable as compared to 302 and 429. The purchase price of the Boss is very high due to the time consumed in constructing it.

Consequently, the parts used to modify the car into a modern Boss 429 are costly. The Boss 429 costs not less than $209,000, and the price can rise depending on alternatives. The Boss 429 parts are very expensive and are rare in the market.

Safety Comparison

The modern Boss 302 brakes automatically sense when the wheels have stopped rotating and regulate the wheel’s pressure to turn. The front-effect airbags have been created to safeguard the head during a frontal crash. Besides, stability management senses when the car’s control limits have been surpassed; hence regulates the engine power and applies brakes to avoid losing control of the vehicle. The Boss 302 is provided with an ignition disable gadget that stops the engine from starting if the legitimate key is not used. Besides, the seatbelt pre-tensioners automatically tighten the seatbelts during an impact.

The Boss 351 has heater controls located at the lower center of the panel, which is out of the driver’s line of sight, hence very dangerous. Additionally, it is not easy to read the writings on the control panel while driving. For the driver to adjust the heating or cooling system, they have to bend forward from the usual driving position, which is so straining.

The Boss 429 has a firewall mounted on the engine backward, which keeps the driver in balance while driving. This model also has a JW3-speed automatic, a steering function to allow energy-efficient steering, which puts the car out of danger.

Features Comparison

The Boss 302 has double headlamps, wide rear quarter panels, and an inbuilt spoiler effect across the trunk lid. It is the best-enjoyed boss car due to its high rpm power, controlling the outcome, and vigorous feel. This model has distinct blocks, carburetor, and heads; therefore, the buyer is supposed to check these elements to ensure they are genuine carefully.

On the other hand, many drivers regard the Boss 351 as the best muscle car in history, which has a lot of competition. The Boss 351 has a high revolution ceiling and a lot of torque, merging the big block and small block engines’ best characteristics. The majority of drivers did not recognize this car due to its poor racing history. Moreover, it had an oil crisis and unpleasant smoke equipment, which hindered the model’s progression. This car was user-friendly, easy to drive, had medium torque and exciting performance.

The Boss 429 has a desirable chrome ring enclosed in a radiator grille surrounding the inner secured beam headlights. It has a narrow front bumper that wraps around each side of the front end and a smooth running front spoiler that keeps the front tires on the ground. Besides, both sides of the grille have a broad functional hood scoop compared to the Boss 302 and 351. The hood’s tip has a series of body lines that converge to a sharp point, adding more uniqueness to the front end.


The Boss 302 name was initially utilized in 1969 as a presentation alternative to compete the Chevrolet. It took few years, but Ford eventually restored the Boss 302 nomination in the 2012 model as the best performing Mustang. This model was also presented with a flying combination motivated by the Boss 302R race car. Therefore, 0-60 mph covers just 4.2 seconds, and the quarter-mile 11.72 seconds, making 302 the best. This model also has fully refurbished after-sales wheels modified to look like vintage Magnum 500 Ford wheels that were discretionally on the Mustang. The car looked classy because of the quad headlights and the dark casings around the exterior lights. Additionally, the track pack brakes and suspension are cheap.

The Boss 302’s fuel consumption is satisfactory for a V8 sports car with Environmental Protection Agency grading 17 mpg in the municipality and 26 mpg on the freeway. If an individual likes Mustangs and needs a classic car, then the Boss 302 is the best noticeable car as it is also the best-observed model of Ford ever manufactured (Rosenholtz 2019). The Boss 302 is the most attractive Mustangs and has the legacy that approves it and its uniqueness. In addition to these characteristics, the new prices are 50% of what one would pay for the new Mustang.