Say what you want about Ford's first-generation Mustang, but one can't deny its impact on the automotive industry and, decades on, the old-car hobby as a whole. The characteristics that contributed to the car's original appeal have been recounted again and again: attractive styling, sporting yet practical dimensions, ample number of standard features and a surprisingly low base price. Ford's all-out introduction advertising blitz was also a noteworthy factor in capturing the hearts of over 121,000 customers in just a half model year alone. Another factor was the ability of owners to personalize their new "pony cars," courtesy of a heavily laden option list, one that happened to include the 271-hp "K-code" 289.
Technically, the "Hi-Po" 289 wasn't even available in the Mustang until June, 1964, a full two months after Mustang's launch, which then knocked the 210-hp D-code 289 down a peg as top engine option. When it became available, however, the lively K-code engine only served to further solidify Mustang's capabilities as a legitimate performance machine during an era when Ford's dominance in auto racing could be seen in just about every discipline of the sport.
Ford's own advertising of the K-code was a direct call to "...those who will settle for nothing less than top performance..." The company provocatively laid out its case for the engine, stating: "Designed especially for the true sports enthusiast, this powerful V-8 provides sports car performance to match Mustang's sports car styling. Buyers intending to enter competitive events, such as gymkhanas or rallies, will appreciate this engine's breathtaking acceleration, over 600 feet in the first 10 seconds from a standing start."
Mustang 2+2 fender emblem was standard trim on the Fastback body.
Included with the "Hi-Po" 289 were a Special Handling Package and a full complement of 6.95 x 14 dual-red-stripe tires. The entry fee for this performance boost: a whopping $442.60 over the additional $75 assigned to the 260-cu in engine option. With the exception of the $283.20 air conditioning, no other factory or dealer Mustang accessory had such an impact on buyer's wallets, which means K-code production was understandably low. Over the course of a three model-year run (technically all 19641/2; Mustangs have a '65 model year VIN), just 13,231 of the nearly 1.7 million Mustangs that rolled from the assembly line were equipped as such: 7,273 from introduction through '65; 5,469 in '66; and a mere 489 in '67 according to Marti Auto Works.
Although the Mustang's reputation as a muscle car was more heartily enhanced with Cobra Jet and Boss engines after 1967, and under the modification guidance of Carroll Shelby, the original K-code performer is no less desirable among today's collectors and is often a bit more affordable compared to its more powerful brethren. Here are some more details behind the inner workings of the K-code Mustangs.
ENGINE
The solid-lifter K-code 289 was not your average Ford small-block. Inside the over-square short-block's four-inch cylinder bores were high-strength flat-top aluminum pistons, which were linked via heavy-duty connecting rods with larger 3/8-inch rod bolts to a higher-nodular cast-iron crankshaft featuring a larger front counterweight to maintain high-RPM balance. Holding the crankshaft in place were heavy-duty two-bolt main bearing caps. Each cylinder head was equipped with 1.78/1.45-inch intake/exhaust valves and screw-in rocker arm studs, while cast-iron header-type exhaust manifolds helped breathing.
If the Rally-Pac was ordered with the K-code, the tach would register up to 8,000 RPM.
Perched atop the cast-iron intake manifold was an Autolite 4100 four-barrel carburetor touting a 600-CFM flow rate, capped by an open-element air cleaner assembly with a chromed lid and appropriate engine callout decals; the rocker-arm covers were also finished in chrome. A dual-point distributor rounded out the build, along with a dual exhaust system featuring an H-pipe, single transverse muffler and twin tailpipes. With a 10.5:1 compression ratio, all told the engine was rated for a stout 271 hp at 6,000 RPM and 312 lb ft of torque at 3,400 RPM. Weighing just 465 pounds, the Hi-Po 289 made for an excellent power-to-weight ratio in the Mustang.
Generally considered a very durable engine, there were only a few running changes made to this 289 and its related operating systems, beginning with a switch to dual mufflers during the full-1965 model year production run. Ford also converted to an alternator-based charging system for the full-1965 model year, as well as to a six-bolt bell housing pattern to provide space for an 11-inch clutch. No upgrades were made in 1966. The K-code was ultimately overshadowed by the 320-hp S-code 390 in '67, which explains its rapid drop in production figures that year.
TRANSMISSION
The caveat to the K-code 289 was that from its introduction through the 1965 model year, only the Toploader four-speed manual transmission was available against it. Not all Ford Toploaders from this era are alike, however. Internal first-through-fourth gearing against the Hi-Po 289 was 2.32, 1.69, 1.29 and 1.00:1, whereas the 210-hp D-coded 289 transferred torque through 2.78, 1.93, 1.36 and 1.00:1 ratios. Reverse gear in the K-code Toploader was 2.32:1.
While the Toploader remained available against the "Hi-Po" 289 through 1967, Ford finally offered a Cruise-O-Matic three-speed automatic for the 1966 and '67 editions. As was the case with the four-speed, the Cruise-O-Matic gearing against the Hi-Po 289 contained different ratios, specifically 2.40, 1.47 and 1.00:1, with a reverse ratio of 2.00:1.
Toploader transmissions are known for their durability against aggressive torque and hard shifts, and have since become the basis for many race car transmissions. Yet even these units can succumb to wear. Like most performance transmissions, however, they--and the automatic--can be easily rebuilt by experienced mechanics using readily available service parts.
DIFFERENTIAL
Unlike other Mustangs, only the K-code models received Ford's ever-durable 9-inch differential prior to the introduction of the 390, as this axle was designated specifically for high output engines when used in Ford passenger models. The number of available final drive ratios, however, was rather limited: 3.50, 3.89 and a performance-friendly 4.11:1. Ford's limited-slip system was available through the 1967 model year as well. As is often the case, the aftermarket now provides a wide range of ratios to suit individual driving styles/purposes.
CHASSIS
One of the aspects of the Mustang that made it so affordable upon introduction was the fact that its unit-body foundation had already been developed for the Falcon. Slight modifications were made, however, such as a reduction in wheelbase to 108 inches to accommodate the new Mustang body. Heavy box-section side rails and five cross members were the key elements for structural rigidity; however, unlike GM unit-body platforms, the Mustang did not incorporate a separate front subframe. Convertibles utilized thicker gauge steel and incorporated reinforcements at specific points.
As mentioned earlier, the independent front suspension and leaf-sprung rear counterpart were automatically upgraded when the K-code 289 was specified. Affected components include the front and rear spring rates, which were increased from 89 to 101 pounds and from 101 to 130 pounds, respectively. Along with heavier shock absorbers, the front anti-roll bar was increased from .69- to .84-inch in diameter, while the steering ratio was reduced to 22:1.
Although subtle differences exist between model years, the most notable alteration to the chassis occurred for the 1967 model year. The Mustang received its first noteworthy redesign, which lengthened and widened the chassis--although the wheelbase remained unchanged--to accommodate the enlarged body and aforementioned inclusion of the 390-cu in engine option. Enlarging the chassis also served to improve the Mustang's overall handling characteristics.
BRAKES
As with most cars of the era, hydraulic drum brakes were standard. For the Mustang, they measured 10 inches in diameter front and rear; power assist was available. So, too, were front disc brakes, utilizing four-piston calipers. With rotors measuring a little over 11 inches in diameter, the discs greatly increased the Mustang's stopping ability; however, power assist was not available in conjunction with the disc-brake system. Changes to the brake system occurred with the 1967 redesign. Power assist was now part of the disc brake system, as was a dual-circuit master cylinder.
WHEELS & TIRES
K-code equipped Mustangs were shod with five-lug, 14 x 5-inch styled steel wheels and dual "Red Band" 6.95 x 14 bias-ply tires throughout the engine's availability. The possible exceptions to this rule were the 15 x 5-inch wheels and the 5.90 x 15 tires that were reportedly standard equipment against the Hi-Po 289 until September, 1964. In addition, 6.95 x 14 blackwall or white-stripe tires were optional starting in 1966.
BODY & INTERIOR
Initially, the Mustang was available in only two body styles--convertible and hardtop coupe--each with stylish side scallops that only served to further accentuate the long hood, short deck appearance. On September 9, 1964, the sleek 2+2 Fastback body style with its functional and racy C-pillar vents was added to the line. Styling updates, such as grille patterns, emblems and some parts of the body, kept the Mustang line fresh each year, while optional trim and vinyl roof treatments continued to personalize each even further. Again, the 1967 redesign, while maintaining the original Mustang appearance, grew 2.50 inches wider and 2.00 inches longer.
Interiors were furnished with vinyl bucket seats, floor carpet and a floor-mounted shifter, along with bright hardware throughout. The instrument cluster had auxiliary gauge pods flanking a horizontal speedometer with generator and oil pressure warning lamps below. A Rally-Pac option added a 6,000 RPM tachometer and clock to the steering column; however, the K-code engine mandated an 8,000 RPM tach when ordered. A center console and a host of comfort options were available each year; a bench seat became available in 1965. For 1966, the instrument panel fully adopted the GT five-dial gauge layout.
GT EQUIPMENT GROUP
Beginning with the full 1965 model year, Ford made available the GT Equipment Group. Available only with the 225-hp and "Hi-Po" 271-hp 289-cu in engines, the package consisted of GT ornamentation, GT stripes, fog lamps and grille bar and a dual exhaust system with bright extensions through the rear valance panel. Additionally it mandated the installation of the Special Handling Package (standard on K-code cars), front disc brakes, and a five-dial gauge arrangement in place of the horizontal speedometer. This gauge arrangement consisted of a central circular speedometer flanked by smaller circular auxiliary gauges; the Rally-Pac was still a valid option against the GT package.
RESTORATION & PERFORMANCE PARTS
Restoring an early Mustang of any type has never been easier with regard to parts availability. Virtually everything from body panels to trim is being reproduced, as well as unit-body subassemblies. In fact, in recent years complete unit-body shells have been remanufactured, including the 1967 fastback.
Mechanically, Mustang parts have been available for decades, while performance upgrades, such as four-wheel disc brakes, are becoming more numerous. Given the nature of the K-code engine option, however, many owners tend to side with OE build traits during a refurbishment or restoration due to its rarity.
Engine
The "K" in K-code Mustangs refers to the engine: a durable, lightweight "Hi-Po" 289-cu.in. V-8, featuring just enough special equipment to help it make an official rating of 271 hp. Until 1967, it was the top engine option available to Mustang.
Brakes
Cast-iron drums were deemed fit for duty with regard to stopping the Mustang, even one with a 271-hp V-8. Power assist was optional. Front disc brakes were also available but were not offered with power assist.
Transmission
Exemplifying the look and feel of a sports car, the K-code Mustangs were offered with a four-speed manual as standard equipment each year. Yet not everyone likes to shift manually, and to that end Ford added a Cruise-O-Matic option in 1966 and '67.
Interior
In spite of the low base price, Mustang interiors were far from pedestrian. Vinyl bucket seats were standard, along with a fine array of trim. Interior décor packages, and the GT package beginning in 1965, only added to the sports car flair.
Chassis
Although it was a small-block, the powerful K-code engine mandated the installation of the Special Handling Package, which upgraded the springs, shocks and front anti-roll bar to heavier units that were mated to the unit-body platform chassis.
Body
Those in the know can tell you that early Mustangs have developed a reputation for corroding significantly in several locations due to the very nature of the car's design. Fortunately, every piece of sheetmetal--large and small--is available to restorers today.
Owner's View
I originally bought this for my wife, Laurie. She said it was cute and fun to drive, both of which I have to agree with. Laurie used to drive the kids to and from events, nights out with her girlfriends and such. I was loading up one of my other cars for a race and she said, 'Why don't you take mine instead?' So I did, and quite frankly I found it pretty amazing.
The K-code 289 is a durable and surprisingly powerful engine that, in stock form, will have no problem running in the mid-14s at the drag strip. As it is now, it's a fun car to race with; I think I'm the first to race an early K-code in the Pure Stock Muscle Car Drags, and I'd be willing to bet that a little fine tuning in accordance with the rules can result in a low 13-second pass at 105 MPH. I've enjoyed this car so much, I'm looking at a K-code GT convertible.--Mark Weymouth
What To Pay
K-code Mustang
Add: Rally-Pac, 5%; Pony Interior, 10%
Note: As with any muscle car, a specific combination of factory build options can result in low production numbers which can produce both private and auction sales anomalies that differ from the averages stated here.
Parts Prices
Brake rotor: $60
Carpet set: $155
Complete 1967 shell, fastback: $15,000
Convertible top: $165
Fender, 1965: $330
Floorpan, complete: $450
Gauges, Rally-Pac 8,000 RPM: $400
Grille, standard: $70
"High Performance" fender emblem: $10
Piston: $20
Quarter panel: $120
Rear frame-rail section: $29
Steering wheel, walnut: $145
Styled steel wheel: $150
Tire, dual red stripe: $175
Club Scene
The Mustang Club of America
4051 Barrancas Avenue PMB 102
Pensacola, FL 32507
850-438-0626
www.mustang.org
Dues: $50/yr • Members: 11,000
