A remedy was in the making, as the 428 Cobra Jet package for the Mustang began its metamorphosis. Instead, Tasca Fordthe second-largest Ford dealership in the world in the 1960sinspired the 428CJ revolution. In 1958, Ford introduced their first line of big block motors, known as the Ford FE engines. Ford had introduced the 385 series in 1968, and the 429 first appeared in the Thunderbird. The engine engineering personnel who worked for me on the 428 program were Paul Lampela, Frank Gondoly, Bob Snider, and Matt Hecht. I have the option to purchase either one of them. The World's largest non biased Shelby Cobra related site! Consequently, Ford used Holman Moodys 428 engine as the inspiration it desperately needed to help reclaim its rightful place at the top of the pony car market. 428 CJ's came in the 69 so it would be more correct as far as appearance goes. Say Cyclone CJ. The new 2008 Ford Cobra Jet Mustangs were built strictly for the drag strip, so they werent even given VINs. I'm not sure about how well a 429/460 fits in '67-70's though. I think, but don't remember, that the SCJ would come in cars optioned with the "drag pack.". Ford quickly caught the vision, and before the drag-ready Mustang returned to Tasca Ford, Ford Engineers removed it from the vehicle so they could reverse engineer it for mass production. Kevin later explicitly confirmed that "Ford did not produce 69 4.30 vehicles with Detroit Lockers. The 428SCJ used 427 LeMans connecting rods and different pistons, crank, wrist pins flywheel/flexplate, a cast-iron Police Interceptor intake manifold, and an engine oil cooler. Compression was either 10.5:1 or 10.6:1, with 10.6:1 taking over from 1969-on. What makes the 428 Super Cobra Jet engine so super? YES! In fact, Ford had seen the writing on the wall. The value of a Cobra Jet will differ, depending on the body style, options, and year of the car. The PI ran stock 390/428 heads, an aluminum intake, the same cam as the CJ and a 600 CFM carb. You cannot really compare 69 with the 74 cars. Because of the long throw, the 428 was more of a low rpm / torque motor were as the 427 was a high rpm race motor. 1969 and 1970 CJ vs. SCJ parts identification. However, Ford ran into a problem. The 427 quickly became one of the most popular and powerful Ford engines, pumping out 425 horsepower. Like the Chevy L-88 was 5 hp less than the trip set up Corvettes, because they lied their ass off to keep people from buying the L-88 who didn't know what they were getting into. As mentioned, the 428 Ford Cobra Jets had 427-style heads, which had 2.09 intake valves and 1.66 exhaust controllers. The axle code in the order image is "8" (which means 3.50:1 open) and the car's data plate has an axle code of "W". Instead, "Tasca Ford"the second-largest Ford dealership in the world in the 1960sinspired the 428CJ revolution. Automotive magazines from 1968-1969 recorded eight of the fastest Mustangs, Fairlanes, Cyclones, and Cougars powered by a 428 Cobra Jet and Super Cobra Jet, ranging from 13.23 to 14.40-seconds in the quarter-mile ET with trap speeds of 99.4-106.6 MPH. now if your talking 429scj vs. 428 scj i would give the nod to the 429scj. 2) Cast iron PI (Police Interceptor) intake manifold. The 427 boasted 390 hp, a full 55 more than you-know-who. The 396 featured advanced-design, canted-valve cylinder heads that flowed like crazy and earned the name "porcupine" because of their splayed-valve arrangement. Cobra Jet engines received low-riser heads with a "rough-cast" combustion chamber (2.09int.-1.66ex. Over the years, Ford has produced some incredibly iconic cars and engines. The difference was forged pistons, solid lifter cam and four bolt mains. For the '70 Torino and Cyclone and the '71 Mustang and Cougar, the passing of the 428 meant a switchover to the new 385-series Ford big-block. Ford released the original 428 in 1966, and in 1968 the Cobra Jet variant was born. Two codes designated a CJ: the R code specified a Ram Air vehicle, while the Q code meant no Ram Air. One had spun on the crank bearing and all would have had to be resized, so Bill advised me. Super Cobra Jet oil cooler adapter Identified by the letter W in the fifth spot of the VIN, this early 1968 edition was the only 427 with hydraulic lifters, an iron intake manifold, a single point distributor, a smog pump (Ford's Thermactor system), an automatic transmission (the four-speed was not available with the 427), and optional air conditioning. Ford discontinued the 429 Cobra Jet and Super Cobra Jet options after 1971, largely due to the increasing emissions restrictions. Just as long as they dont add gimmicky speakers with faux-engine noise, like some of their competitors. The 385-series 429 and 460 are also good street-strip engines, with their canted valves and large bearings. While the torque claim was in line with expectations, many wondered why the big 428 CJ was only 10 ponies ahead of the 325hp 390 GT four-barrel mill. Whereas Shelby had scrapped plans to redesign the 428s intake manifold a notorious choke point Tasca came up with a different idea. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. In 1967, this changed when they put the first generation 390 big block in the Mustang. The Police Interceptor contained an aluminum intake, high performance camshaft and beefier connecting rods to produce 360 hp. The CJ block differs from the plain 428 due to the additional webs cast into the main bearing saddles. The 428 Cobra Jet was born by drag racers at a Ford Dealership to nudge FoMoCo in the right direction when they needed it most to help recapture the pony car market. The 351 Cobra Jet is also known as the Q-Code 351, due to its RPO. The 1969 description says that the Drag Pack option is "Available only with 428 CID 4V Non-Ram or Ram Air engines" and "Not available with other optional ratio axles or air conditioner". The rarest of the bunch are the 68's. The most vaulable Cobra Jet is the 1968 Shelby GT500KR convertibles, which can go for as much or more than a BOSS 429. However, it wasn't Ford Engineers that first developed this impressive powerplant. All of this was a step in the right direction, but the '67 GT500 was still slower than the rip-snortin' 375hp 396 Camaro. Although the 390 had been offered in the Mustang, the FE had seen incarnations of up to 428 ci. A whole host of high-performance parts was available for the 396 from the Corvette larder, which further complicated matters in Dearborn. Yet, Ford did not use any of the second generation big blocks in pony cars like the Mustang at first. - i dont know much about 428's but im looking into buying a boat that has a 428 in it. The Electric Ford Cobra Jet Mustang can blast through the quarter-mile in just 8.12 seconds at 172 mph, annihilating any Mustang that has ever been in production. Still, a '71 'Jet had a 0-60 time of 6.5 seconds and a quarter-mile time of 14.1 seconds, so it was no snail. Most 428s in 7 liter [COLOR=#0000ff! The 428 was available as a 68 1/2, 68 and 70 model. The V-code designated a 3.91:1 rear axle ratio, while the W-code meant a 4.30:1 rear axle ratio. The back of the CJ block should have a "C" cast or welded into the back of it. 428 FE police interceptor versus cobra jet - Club Cobra FE Forums sponsored by Keith Craft Inc. In the August 1968 issue of Super Stock & Drag Illustrated magazine, a 68 Cougar XR7-GT tripped the quarter-mile in 13.23 seconds, traveling at 103.4 miles per hour. The most comprehensive guide to detailing a 428 Cobra Jet ever published. Super Cobra Jet harmonic balancer counter weight, 3 All 428's had 2-bolt mains also. If the 69 428 is the real deal buy it. A police interceptor may have an "A". That didnt happen until 69. According to Ford themselves, independent dynos showed electric Cobra Jets making north of 1,500 wheel-horsepower. http://www.mercurycougar.net/gallery/showgallery.php/cat/500/ppuser/5281/perpage/12/sort/1, http://www.428cobrajet.com/facts.html#five. The later piston, which appears starting around December 1968, is marked "428" and "SUPER" (thanks to Randy Pollock for the picture), and differs from the earlier pistons by having additional metal in the pin boss area. The 715 was a Ford replica of a Rochester carb, and was fitted to the base Cobra Jets. Well, there you have the top 8 fastest 428 Cobra Jets. Competition was tough in the late '60s, with both GM and Chrysler offering up serious big-block performance. With the elimination of the 428 Ford Cobra Jets after 1970, this left only the measly, low compression 351 Cobra Jet as the only one remaining for 1972-74. You can use the 428 crank in the 390 block and will end up with 410 cubic inches (Ford actually had a 410 for a couple years). These were sold as part of the Drag Pack option. Luckily, Tasca Ford pioneered a high revving 428 engine nicknamed the KR-8 as a direct replacement for the low-revving 390 FE engine. In April 1968, Ford released its own version of the 428 engine and called it the Cobra Jet.. In the 1969 Supercar Annual magazine, one ran a 69 Cougar Eliminator ran a 13.90-second quarter-mile time with a 101.2 miles per hour trap speed. This explains why Ford went with the 390 in the Mustang instead of the 427. When the Camaro hit the streets with a 396ci engine borrowed from the Chevelle parts bin, Ford knew it had competition. Keith, Cobra Make, Engine: ERA Street Roadster #782 with 459 cu in FE KC engine, toploader, 3.31, also police interceptors had solid lifters and adjustable rockers---GT & CJ were hydraulic, Cobra Make, Engine: CSX #4xxx with CSX 482; David Kee Toploader, Reading this brings up a question that I've always wondered about. The 429 SCJ was a stronger version on the CJ. The back of the CJ block should have a "C" cast or welded into the back of it. 8th Place: 1970 Ford Mustang Mach 1 428CJ, 3rd Place: 1969 Ford Mustang Mach 1 428CJ, 2nd Place: 1968 Ford Mustang 428 Cobra Jet, 1st Place: 1968 Mercury Cougar XR7-GT 428CJ, more significant than 335 horsepower advertised ratings, Tasca Ford pioneered a high revving 428 engine, Top 10 Craziest Muscle Car Paint Colors from the Factory, Top 50 Fastest Classic Muscle Cars (1962-1973). These had the larger 600 cfm 4100. Get exclusive muscle car content, giveaways, and a FREE Report on 10 of the most powerful muscle cars ever made right to your inboxabsolutely free! There were slight differences in the base and higher trim Ford Cobra Jets, yet they were all rated the same 335 horsepower, likely meaning Ford was really sandbagging the numbers the whole time. By 1974 the emissions crap that was added to the engine killed the power. In the quarter-mile, a one-second difference is a lot of car lengths. By far and away the most common -- they made 100,000+ of these. Your email address will not be published. In '69 the 351 was good for either 250 or 290 horsepower, depending on its carburetor configuration, while the four-barrel 390 dropped somewhat to 320. 3) An oil cooler Most 428 Cobra Jet fans have heard of the "Detroit Locker" differential, a positive locking differential that was originally produced by Detroit Automotive Products Corporation (DAPCO) and is now available from TracTech Inc. 390 and 428 are different. although the fastest factory car i have ever been in was and is to this day the 68 428scj mustang, and those cars are cars of record winning the 68' winternationals against the Hemi cars. stronger. To date I've only seen documentation for one such anomaly: 9R02R103630, built with a W-code 4.30:1 rear axle and a standard CJ engine. Ford really got it right with the 1968 428 Cobra Jet (CJ). In order to keep the car eligible for the stock NHRA category, Ford capped power at 430 horsepower. (The hood scoop works.) The package included special capscrew-type connecting rods borrowed from the Ford GT Mark IV 427 Le Mans engine. 428 CU IN stuff I copied from the net: Introduced in 1966 Bore and stroke of 4.13X3.98 Cast iron crankshaft forged-steel connecting rods cast iron intake manifold 345 horsepower @ 10.5:1 compression ration Variations of the 428 existed throughout its' life span, including the 428 Police Interceptor, 428 Thunderjet and 428 Marauder. The 428 uses a crank with a 3.98 inch stroke and a 390 has a 3.78 inch crank. Untamed European elegance indeed. The 428's and 429's most associated with Cougars are Cobra Jets. A special option available for 1969 in the Cobra Jet Mustang included a 428 with internal modifications. A lot of people try to pawn off a 390 as a 428. the blocks are nearly identical and the stroke is close. However, there were a few key internal differences between the two engines. Good luck. Cobra Jet Mustang production continued into 1970. It was very similar to the standard 351 Cleveland engine, but with a few key differences. Factory horsepower and torque ratings were the same for both CJ and SCJ engines. Originally available in any of the three Mustang body styles--coupe, fastback, or convertible--all '68 CJ Mustangs are highly sought after, even 30 years later. * These are service part numbers, not engineering numbers. At the same time, a Ford dealer named Bob Tasca was also looking to get more power out of his 390-powered Mustangs. The 429s are also known as the 7.0 Lima V8s, due to their metric displacement. Sunroof has a big brain. Introduced in 1958 for service in fullsize Fords as well as the Thunderbird, the FE had seen a long and colorful career. Whenever a . The Formal Roof versions were the ultimate sleeper, looking like your average everyday grocery getter to any unsuspecting contenders that pulled up next to it at a red light. Carroll Shelby, famous for his GT350 version of the Mustang as well as for the Cobra, became involved when he decided to produce a big-block version of his Shelby Mustang GT series. Cast iron intake manifold identical to the aluminum one on the police interceptor. In four years of its existence, the Cobra Jet name became synonymous with high-performance. Piston part numbers are marked (R) for red size and (B) for blue size to note options for selective fit based on normal production tolerances. As it turned out, the 427 heads massively improved both low-end torque and top-end power on 428. Ky, Cobra Make, Engine: CSX4761, KCR Shelby Alloy 496,760hp, My 427 racer buddy gave me a nos set of c6ae lemans rods,he strongly cautioned me to replace all the bolts with arp ,even though they have never been torqued,he told me in the 70's they went thru a rash of windowing new motors and was told by holman moody that of the ford rod bolts at least 25 percent were fualty out of the box,that would ruin your day to say the least,,huh ? Actually, about 400 hp were on tap in this incarnation of the 428. The 428's and 429's most associated with Cougars are Cobra Jets. Chevrolet wasn't Ford's only problem in the performance department. All Rights Reserved. All of the new Ford Cobra Jets are supercharged, except the Cobra Jet TT from 2013 that has twin-turbos. Starting in February 1969 this complete package could be ordered as the "Drag Pack" option. Midway through the 1967 model year, the 427 was swapped out for a newer 428 Cobra Jet engine equipped with a Holley four-barrel carburetor. In response to the Camaro, in mid-1967 Carroll Shelby created the first Shelby GT500 Mustang. Everyone at Ford was confounded, and the brass didn't want to go back to the 427 because of the high cost of its heavy-duty internal components. Representation from nearly all Cobra/Daytona/GT40 manufacturers Help from all over the world for your questions Build logs for you and all members Blogs The Cobra Jet package added $287.60 to the sticker price of a Cyclone. A police interceptor may have an "A". But there was one thing about the 428 CJ that left everyone puzzled. 22 Though some claim the 428 CJ actually made in excess of 400 hp, we observed 365.1 hp at 4,800 rpm, almost 10 percent more than advertised. Incredibly, he too put a 428 cid block in his Mustangs, but he took it a step further than Shelby. Whenever a differential with a gear ratio of 3.91:1 or 4.30:1 was ordered as an "optional axle ratio" at a cost of $6.53, a lot more than just lower gears came with the package. : For registered members this ad will NOT show, Cobra Make, Engine: Unique Motorcars (sold). For improved high speed reliability, the SCJ used the . Tim K, Cobra Make, Engine: Shell Valley- smallblock grenade w/ the pin pulled. The 351 Cobra Jet was the final Cobra Jet engine that Ford released, and it lasted from 1971-1974. See if you can determine if these motors you are looking at are CJ's. The 429/460 is going to be the cheaper of the engines to build. In 2020, Ford came out with the most unique Cobra Jet in history, the All-Electric Mustang Cobra Jet 1400. However, a 4-speed option was also available. http://www.clubcobra.com/forums/fe-talk/10782-another-dumb-question-428cj-vs-428scj-whats-difference.html, https://www.hemmings.com/magazine/hmn/2009/04/Ford-429CJ-and-429SCJ-V-8/1796187.html. I have a 428 FE engine in my car from back in the day (60's). Cobra Make, Engine: Everett-Morrison LS1, IIRC look at the exhaust manifold bolt pattern-------------the 390GT and 428CJ had a different bolt pattern (had some more holes and an tab on the head for the pattern--the standard engines only had the vertical pattern with a bolt at top and bottom of port, Cobra Make, Engine: Kellison Stallion 468 FE, Cobra Make, Engine: Kirkham 427 brushed aluminum with Keith Craft 527C.I. As with most deceptions, the ruse was quickly unmasked as the NHRA factored the 428 CJ into higher classes so it couldn't bully weaker machinery. The basic strength of the Super Cobra Jet engine is in a more durable reciprocating assembly (crank, rods, pistons, wrist pins, flywheel/flexplate, and harmonic balancer) that was designed to withstand the higher RPM requirements of drag racing. Ford advertised the 428 Cobra Jet's horsepower at 335 (10 less than the Thunderbird) with 440 lb-ft of torque, and whether those numbers were accurate or not they didn't push past the 390 far enough to generate more than passing interest from the Mustang crowd for its inaugural 1968 year. I won Winter Nationals at Beeline Dragway in DStock Class at 13:05 118 mph in 1970 with my 428 CJ Mach. Last edited: May 19, 2013 FrozenMerc, May 19, 2013 SHARE POST #3 hoop98 Member The program was engineered, designed, tested, validated, released, and certified between January 1967 and August 1968. The CJ block differs from the plain 428 due to the additional webs cast into the main bearing saddles. The new Mustang was beautiful, and it had a large enough engine bay to take the big mill. Many aficionados of the Cobra Jet Mustang consider the '70 version to be the nicest of all, combining the last year of the FE engine with the last year for the '69-'70 body style. Why wouldn't an aluminum headed 351W be the best option -- then you don't have to change the rest of the driveline. The package was also available in the Torino, the Fairlane, and the Mercury Cyclone. The 390 Mustang was getting abused at the drag strip by Chevrolets new 396 powered Camaro. While the Cyclone was named the fastest car of the year, having set a world record speed of 189.22 miles per hour at Daytona, the 428 version wasnt the fastest in the quarter-mile, achieving 18th place overall. The Super Cobra Jets got forged aluminum pistons and higher performance camshafts, as well as a high-rise intake manifold. The 428CJ also used a superior cast iron intake and better exhaust manifolds. The Mercury Cougar underwent styling updates in 1969, including transitioning to Coke bottle styling and eliminating side vent windows. The 428SCJ was externally balanced with a counter weight behind a different harmonic balancer than the 428CJ. Sales success of the Mustang had been phenomenal in its first two years, and Ford wanted more. The 429 blocks are incredibly solid, and the Cobra Jets got a high nodularity, Brinnel tested crank and forged rods. The 1975 MPC also excludes 1970 from the list of application years for the C9ZZ-13826-A bracket -its only listed for the 1969 Mustang equipped with a 428-4V or Boss 302 engine, but it was also positively used on the 1969 Boss 429 as well! The C blocks started to be used in mid 1967 before the CJ production started. Mustang buyers who selected either of the optional 3.91:1 or 4.30:1 rear end gear ratios got more than just an optional axle ratio! In its August 1968 issue, Motor Trend Magazine reported a 13.86-second ET, traveling at 101.69 miles per hour. chuck, The same naming convention was applied to the 429 engine as well. Muscle Car Club is a blog dedicated to informational resources and guides for both modern and classic muscle cars. The C marking on the rear face of blocks predated the CJ era. The Cobra Jet (original 428) was put together from parts from the Ford parts bins, the rods and heads were used in earlier engines but aren't referred to by any other name than Cobra Jet since. It was available in the new Camaro in 325-, 350-, and 375hp forms (a 425hp version had been available in the Corvette for '65). Pontiac had its GTO as well as the new twin sister to the Camaro, the Firebird, and each was available with a 400ci engine. It was only installed in mid-size (1970-71) and pony cars (1971 only). The 429 heads were incredibly free flowing, and in reality some of the best Ford big block heads ever created. Known as the Thunderbolt, this Fairlane saw very limited production and was built as a factory lightweight race car. Unlike the 351, Ford based the 428 Cobra Jet and Super Cobra Jets on the FE series of engines. 1968 was the only second year of the Cougar, which only received minor revisions, including side marker lights and front shoulder belts. Although many early Mustang articles suggest that the 428 Cobra Jet was designed by Mr. Tasca, there are in fact more than 30 design differences between the components used by Mr. Tasca, the 428 PI, and the released 428 CJ. The Cobra Jets are very similar to the standard 428s, with only minimal upgrades for better performance and reliability. The 428 CJ cylinder heads featured an un-machined chamber of 73-76cc, 2.06" intake valves and 1.66" exhaust valves. Now lets take a look at the various Ford Cobra Jet engines. It had four bolt mains, aluminum hemi-style heads and looked like no other engine. However, it wasnt Ford Engineers that first developed this impressive powerplant. 428CJ /SCJ cars used shock tower reinforcements, thicker front sway bars, and beefier springs and shocks. The factory power rating seemed to be a typo. A common misconception seems to be that SCJs were originally equipped with forged pistons and CJs were originally equipped with cast pistons. You true FE gurus can add/correct info to the above. Super Cobra Jet Connecting Rod Credit: CarsRememberWhenAutoSales/Wikipedia. . To verify an original car, you can simply look at the vehicle identification number (VIN) on the dashboard. The CJ came in the GTs place, powered by a 428CJ and a Spoiler variation that appeared midyear with a standard rear wing. Pioneered in 1967 as a stripped-down Holman and Moody prepared drag-ready Mustang for Tasca Ford, the 428 short block with 427 heads christened the KR-8 flawlessly balanced proven race engineering with factory Ford parts. Not Ranked. The two-barrel 390 was good for 265 horsepower, the four-barrel stepped up to 325, and the Cobra Jet 428 provided just ten additional horses but a fair torque boost to go with it. Massachusetts. FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428) - difference in 428 blocks? All FE dampers are neutrally balanced, so all can be interchanged between motors if you understand the pulley requirements. Combined with their burgeoning competition with the new Chevy Camaro, Ford decided to put a modified 428 heavily based on Tascas 428 into the Mustang for 1968. The 406 was essentially a bored 390, and in 1963 Ford went even bigger and bored the 406 out to 427 cid. The 428 Cobra Jet powered some of the fastest Ford Muscle Cars from 1968 to 1970, over nine Ford and Mercury models. They did so to honor the 1968 Mustangs that won the NHRA Winternationals, and inaugurated the first Cobra Jet era. They were almost identical to the standard Cobra Jets, but had stronger internals. The 1969 Mercury Cyclone continued on the Montego platform in the fastback form, and the GT was no longer a model, available as an appearance-only package. Royce: thanx for the clarification. Be sure to subscribe if you like content like this! 429 Cobra Jet and Super Cobra Jet Vehicle Applications. In the 1969 Supercar Annual magazine, one ran a 13.94-second quarter-mile time, traveling 101.7 miles per hour. Actually, rebuilding a 428 using modern methods costs significantly MORE than $2,500. important]cars[/COLOR] will have heads with the smaller valves and a lesser highway friendly springs . In the quarter-mile, a one-second difference is a lot of car lengths. The 428 is a 1969 block no heads. Note that it was not thought to be possible to order an SCJ engine by itself -- the only way to get your hands on an SCJ in a Mustang was to order the optional 3.91:1 or 4.30:1 rear end gear ratios. With more than 400 lb-ft available from 2,600 to 4,700 rpm, the Mach 1's tail is sure to be obscured in clouds of tire smoke. I'm not embarrased to ask anything anymore. Ford introduced their second generation of FE V8 big block engines in 1962 with the 406 cid big block. Either way, you can be guaranteed it will be a monster at the drag strip and not be lacking for power. Reportedly, they didnt even let Tasca leave with the car. Be sure to check the bore 4.13 and measure the distance between the cylinder cores. None of the parts of the 428 SCJ reciprocating assembly interchange with their 428 CJ counterparts. The Cougar was available in either standard or XR-7 trim, with option packages including the GT and the performance-trim Eliminator. Four decades after its initial release, and 34 years after it was discontinued, Ford brought back the Cobra Jet badge in 2008. The main bearing journal diameter measures between 2.7484 and 2.7492 inches. non biased Shelby Cobra related site! At the '68 NHRA Winternationals in Pomona, California, Ford entered a number of specially warmed-up '68 Cobra Jet Mustangs. However, buyers would have to order the GT package if they wanted to get their hands on one in 1968available in either a coupe or fastback body style. Cast iron exhaust manifolds. Also, there is an S between the 8 & the C Cobra Make, Engine: I Wish, Just an old truck with an FE, Cobra Make, Engine: Kirkham 427 (KMP 266); CAV GT40, also forged pistons,and an electronically balanced crank shaft on the SCJ;all reliability issues not HP ones. The 428 Cobra Jet powered some of the fastest Ford Muscle Cars from 1968 to 1970, over nine Ford and Mercury models. Compression ratios were lowered considerably, and with this, performance often went out the window.