Everything about the 1971, 1972 & 1973 Ford Mustang

The Ford Mustang is hands-down one of the most popular cars ever produced. A runaway success from the start, 41 years ago, there are millions of them still on the road. Although the majority of Mustang aficionados are drawn to the 1964-1/2 through the 1970 model, the 1971 to 1973 Mustangs, which were never as popular as the earlier models, are the most affordable of the “early Mustangs” to buy today.

The 1971-73 Mustang was available in five different body styles, with the Grandé version the most forgotten model of them all. The Grandés, which came in coupe form only, are good-looking cars and, in contrast to their 1960s counterparts, are reasonably priced, offer the same driving enjoyment and, because they share many parts with other models, are easy to restore with thousands of parts available from numerous suppliers.

The Grandé coupes focused on luxury, as reflected in their somewhat lofty $3,212 list price. Looking sophisticated with their padded vinyl roofs and deluxe wheel covers, the Grandé was available with any engine option, which permitted buyers to order themselves a real sleeper.

During the early 1970s, the new car market was changing. Higher insurance rates, increasing environmental demands and a different market transformed high-horsepower cars into overweight luxury cars. The Mustang suffered along with the others. In 1969, nearly 300,000 Mustangs were sold; by 1972, that number fell to 125,000. The once-revered Mustang fell into the grip of a decade-long identity crisis. The buyer of a new 1973 Mustang found a car little changed from the two previous years, but despite the likeness, nearly 10,000 more were sold in 1973 in contrast to the year before. Like most cars of that era, the Mustang gained weight and grew in length; in fact, it was the longest Mustang ever, at more than 16 feet. The weight gain was due to new federal bumper standards, but Ford engineers did an admirable job of keeping the Mustang handsome in contrast to other Ford products.

There were numerous options available, ranging from the cheapest-$6 door edge guards-to the most expensive, a, 275hp V-8 in 1972 at about $870. Sales figures showed a shift to comfort and convenience in contrast to high-performance equipment. For example, in 1973, more than 90 percent of the Mustangs had automatic transmissions. Nearly 93 percent had power steering, 78 percent had power brakes, 62 percent had tinted glass, and 56.2 percent had air conditioning.

The entire Mustang engine lineup was available in the Grandé. All 1971-73 engines were of an overhead-valve design and rock-solid reliable with cast-iron blocks and cylinder heads.

The standard engine in the 1971 Grandé was the straight-six producing 145hp at 4,400 rpm. This economical engine has a 3.68 x 3.91-inch bore and stroke, 9.0:1 compression ratio and breathed through a Motorcraft single-barrel carburetor. The seven-main-bearing block featured hydraulic lifters.

The smallest engine on the option list was the V-8, with 9.0 compression and 210hp at 4,600 rpm. It featured a 4.00 x 3.00-inch bore and stroke. There were three optional V-8s, all had a 4.00 x 3.50-inch bore and stroke. The least powerful developed 240hp at 4,600 rpm with a Motorcraft two-barrel carb. The second 351 produced 285hp (through May 1971) and 280hp after that at 5,400 rpm. This V-8 had a Motorcraft four-barrel. The top-of-the-line 351 featured 330hp at 5,400 rpm, 11.1 compression and a Holley four-barrel carb.

For performance-minded Grandé buyers who wanted big-block power, there were two V-8s: the Cobra Jet with 11.3 compression, and the Super Cobra Jet with 11.5 compression. The Cobra Jet had a hydraulic camshaft and made 370hp at 5,400 rpm and the Super Cobra Jet with its solid-lifter cam developed 375hp at 5,600 rpm. Both 429s had a 4.36-inch bore and 3.59-inch stroke and Holley four-barrel carburetors.

With their horsepower now rated net instead of gross, the engine lineup for 1972 changed drastically. The 429 was gone, and lower compression ratios took their toll on horsepower as the straight-six engine was down to 98hp, the 302 had 140hp, and the two optional 351s had either 200hp or 275hp.

Solid-lifter camshafts were no longer offered, and Ford, like the other manufacturers, was getting ready for the advent of unleaded fuel. The downward horsepower slide continued into the 1973 model year. There were four engines, the standard six-cylinder, the 302 and two 351s. The power ranged from 98hp in the straight-six to 248hp in the Q-code 351, which had a Holley four-barrel carb.

“These engines are stout and reliable, but if bored-out too much, they are prone to overheating,” said Frank Druce Jr., who has built many Ford engines at The Boss Shop in Springfield Center, New York. “Unless you get the cylinder walls thin, they are very reliable. If you bore them .020 or .030 over, you are asking for trouble. Otherwise, these engines take easily to modifications. The 302 and the Boss 302 are the best engines Ford ever built,” he said. Paul McLaughlin, who runs the Mustang Owners Club International, has owned a red 1972 Mustang since 1986 and has put nearly 100,000 carefree miles on the car, which features a 302 two-barrel. “I’ve never had any trouble with this engine, and I drive this car every day. This is certainly one of the best engines ever built.”

There were six transmissions available all three years: a Ford-built three-speed manual, two four-speed manuals, C-6 automatic, C-4 automatic and FMX automatic. All transmissions featured sporty floor-mounted shifters. The FMX automatic, while not as well known as the C-4 or C-6, was used in the V-8-equipped models. The four-speed manual was a Ford Top Loader, which gets its name because the gears are put into the transmission from the top, and was made by Ford, as were all their automatic transmissions. McLaughlin says all the transmissions, with a good maintenance record, should provide reliable service.

The differential is a standard hypoid type with semi-floating axles. There were numerous axle ratios: 2.75, 2.79, 3.00, 3.25, 3.50, 3.91 and 4.11. Ratios in 1972 and 1973 were the same, but no longer was the low 4.11:1 ratio offered. Traction-Lok and Detroit Locker rear ends were also available. Detroit Lockers, which do not use friction plates, springs or cones, have legendary reliability and are considered one of the strongest rear axles available.

The front suspension features independent upper and lower control arms, coil springs, ball joints, strut rods, an anti-roll bar and tubular shock absorbers. The rear suspension features a live axle on longitudinal semi-elliptic leaf springs and tubular shock absorbers. Grandés equipped with the 351, Boss 351, 429 CJ and 429 CJ-R V-8s had rear shocks that were staggered in their location. This arrangement had the right shock ahead of the axle and the left shock behind it. By doing this, Ford was able to reduce rear axle windup during hard acceleration. The standard shock setup had both shocks in front of the axle. A rear anti-roll bar was part of the competition suspension package, which was standard on V-8-equipped cars but optional on other models.

Grandés equipped with either the straight-six or V-8 were fitted with 10-inch-diameter drum brakes with 2.25-inch-wide linings; 351- and V-8-powered Grandés had wider 2.50-inch brake linings. In the rear, the 10-inch-diameter drums featured 1.75-inch-wide linings; this increased to 2 inches wide for those models fitted with the more powerful 351 and 429 V-8s.

Power-assisted front disc brakes with floating calipers were optional. The discs measured 11.3 inches in diameter and were matched with meaty 3-inch-wide brake linings in the rear.

Total brake swept area for the 250/302-powered models with drum brakes was 251.1 inches and 282.8 inches for the 351/429-powered models. The total swept area for the disc brake setup was 356.6 inches. As with most Mustang mechanicals, brake parts are inexpensive and simple to find almost anywhere.

Like all Mustangs, the Grandé had an all-steel body. “These cars rust very badly,” says John Balow, owner of Muscle Car Restorations in Chippewa Falls, Wisconsin. “The biggest cause of rust on these particular cars is not really road salt, but moisture. Due to the gas tank installation design and the fact that there are no drain holes, water lies in the trunk and begins the rot process; the water comes in from the rear window area.” They are also prone to rust in front of and behind the rear wheels. Balow says water and dirt get down behind the quarter glass and rot the quarter panels from the inside out. McLaughlin adds, “The dog legs behind the front wheel and rear wells rust, as do the trunk floors and area around the taillamps. Mustangs are uni-body and have sub-frames front and rear, but unlike a Camaro or Firebird, they are not easily removable. However, when replacing rusty floors, you do not have to remove the sub-frames.” McLaughlin advises that the body and door openings be braced while replacing the floors to prevent the body structure from twisting. While working on these cars, restorers also brace the firewall and the area behind the back seat. Balow warns, though, that not as many reproduction body panels are available for the 1971-73 models as for the earlier Mustangs.

Some of the features that were standard on Grandés included high-back bucket seats with Lambent clot insert, deluxe instrument panel, woodgrain appliqués on the center dash, molded door panels, electric clock, rear ashtray, bright pedal trim and courtesy lamps.

Some door panel trim is hard to come by, and center consoles are getting tougher to find.

New seat covers, carpet sets and just about every other interior part needed to restore 1971-1973 Grandé Mustangs are readily available.

The vinyl used on the roof was durable and long lasting. But if the vinyl covering had split and water seeped underneath, the metal roof below could rust. The vinyl was available in either black, white, blue, avocado, ginger or brown.