Editing Muscle car (section)

=== 1964–1970: Peak muscle car era ===
[[File:1966 & 1969 Pontiac GTO (34841847634).jpg|thumb|right|1966 & 1969 [[Pontiac GTO]]]]
[[File:1970redGTX.JPG|thumb|right|1970 [[Plymouth GTX|Plymouth GTX 440]]]]
[[File:1970 AMC Rebel "The Machine" (28293464911).jpg|thumb|1970 [[AMC Rebel#The Machine|AMC Rebel "The Machine"]]]]

Although pure muscle cars often sold in relatively small volumes, manufacturers valued the [[Halo effect#Branding|halo effect]] of the publicity created by these models. Competition between manufacturers led to a horsepower war that peaked in 1970, with models such as the [[Chevrolet Chevelle#1970|LS-6 Chevelle]] advertising as much as {{convert|450|hp|kW|0|abbr=on}}.<ref>{{cite web|url= https://heacockclassic.com/articles/the-best-muscle-car-1970-ls-6-chevelle/ |title=The 1970 LS-6 Chevelle Was America's King Of The Streets |website=heacockclassic.com |access-date=July 5, 2018 |editor-first=Paul |editor-last=Zazarine |date=November 14, 2014}}</ref>

The [[Pontiac GTO]], a car that captured the public mind and strongly influenced the muscle car era, was introduced in 1964 as an optional package for the intermediate-size Pontiac Tempest. The GTO was developed by Pontiac division president [[John DeLorean]] and was initially powered by a {{convert|389|cuin|L|1|abbr=on}} V8 engine producing {{convert|325|hp|kW|0|abbr=on}}. The success of the GTO led other GM divisions to develop muscle cars based on intermediate-sized platforms: the 1964 [[Oldsmobile 442]], 1964 [[Chevrolet Chevelle#Chevelle SS|Chevrolet Chevelle SS]], and 1965 [[Buick Gran Sport]].

The AMC V8 engine was enlarged to {{convert|390|cuin|L|1|abbr=on}} in 1968,<ref>{{cite web |title=AMC V8 engines – history, descriptions, and more |url= https://www.allpar.com/threads/amc-v8-engines.229904/#post-1085224002 |first=Mike |last=Sealey |website=allpar.com |date=16 November 2020 |access-date=27 August 2023}}</ref> which produced {{convert|315|hp|kW|0|abbr=on}} and was first used in the 1968 [[AMC Rebel#1968|AMC Rebel]] SST,<ref>{{cite web |title=Sharp Restoration: 390/727 1968 AMC Rebel SST |url= https://bringatrailer.com/2016/11/28/sharp-restoration-390727-1968-amc-rebel-sst/ |website=bringatrailer.com |access-date=3 February 2019 |date=28 November 2016}}</ref> [[AMC Javelin#First generation|AMC Javelin]] Go-package, and [[AMC AMX]].<ref name="marlin">{{cite web|url= http://musclecars.howstuffworks.com/muscle-car-information/amc-muscle-cars.htm |title=AMC Muscle Cars |website=How Stuff Works |date=20 December 2006 |access-date=14 February 2022}}</ref><ref>{{cite web |url= http://blogs.discovery.com/velocity/2012/03/how-about-some-love-for-the-amx.html |title=How About Some Love for the AMX |date=25 March 2012 |first=Bill |last=Stephens |publisher=Velocity by Discovery |access-date=18 January 2016 |archive-date=5 May 2013 |archive-url= https://web.archive.org/web/20130505022601/http://blogs.discovery.com/velocity/2012/03/how-about-some-love-for-the-amx.html }}</ref> A staid and distant fourth behind Detroit's "Big Three", AMC hired Dick Teague as a designer, who later became the vice president.  The clean sheet Javelin pony car and two-seat Corvette-competitor AMX were bold moves, and moved AMC directly into the era's "horsepower wars".<ref>{{cite web |title=Evolution of the American Motors AMX-The Other American Muscle Car |url= https://heacockclassic.com/articles/evolution-of-the-american-motors-amx-the-other-american-muscle-car/ |website=heacockclassic.com |date=13 May 2019 |access-date=31 October 2021}}</ref>

As the 1960s progressed, optional equipment and luxury appointments increased in many popular models of "performance-oriented" cars. With the added weight and power-consuming accessories and features, engines had to be more powerful to maintain performance levels, and the cars became more expensive. In response, some "budget" muscle cars began to appear, such as the 1967 [[Plymouth GTX]],<ref>{{cite web|url= http://musclecars.howstuffworks.com/classic-muscle-cars/1968-plymouth-gtx.htm |title=1968 Plymouth GTX |work=How Stuff Works |date=9 January 2007 |access-date=14 February 2022}}</ref> the 1968 [[Plymouth Road Runner]],<ref name=carlife>''Car Life'' January 1969.</ref> and the 1968 [[Dodge Super Bee]]. In 1969, the Plymouth Road Runner was awarded ''Motor Trend'' magazine's Car of the Year.<ref>{{cite magazine |last=Sanders |first=Bill |title=Road Runner |magazine=Motor Trend |date=February 1969}}</ref> With optional performance parts such as intake and exhaust manifolds, upgraded carburetor, and drag-racing tires, the Road Runner had a quarter-mile time of 14.7 seconds at {{convert|100.6|mph|abbr=on}}. In this customized form, the cost of the Road Runner was [[United States dollar|US$]]3,893.<ref name=carlife/>

The [[Plymouth Barracuda]] was a [[pony car]] that could be turned into a muscle car with the addition of the famed Chrysler [[Chrysler Hemi engine#Second generation: 426|426 Hemi]], available as an option beginning in 1968, after debuting in street form two years earlier in the [[Plymouth Belvedere]], [[Dodge Coronet]], and [[Dodge Charger]]. Originally based on the smaller [[compact car]] body and chassis of the [[Plymouth Valiant]], the Barracuda was also available with a {{convert|383|cuin|L|1|abbr=on}} V8 engine producing {{convert|300|hp|kW|0|abbr=on}}. It could run a quarter-mile in 13.33&nbsp;seconds at {{convert|106.50|mph|abbr=on}}on the drag strip. The base price was $2,796.00; the price as tested by ''Hot Rod'' was $3,652.<ref>{{cite magazine |last=Kelly |first=Steve|title=Barracuda on the Line |magazine=Hot Rod |date=December 1968}}</ref> The related 1970 [[Plymouth Duster]] was powered by a {{convert|340|cuin|L|1|abbr=on}} V8 engine producing {{convert|290|hp|kW|0|abbr=on}}. Performance figures were 0 to {{convert|60|mph|abbr=on}} in 6.0 seconds and the quarter-mile time of in 14.7&nbsp;seconds at {{convert|94.3|mph|abbr=on}}.<ref name=duster>{{cite web|url= http://musclecars.howstuffworks.com/classic-muscle-cars/1970-plymouth-duster-340.htm |title=1970 Plymouth Duster 340 |website=How Stuff Works |date=10 January 2007 |access-date=14 February 2022}}</ref>

The {{convert|427|cuin|L|1|abbr=on}} [[Chevrolet big-block engine#427|Chevrolet L72]] big-block engine became available in the mid-sized [[Chevrolet Chevelle]] in 1969 as the COPO 427 option. The 427 Chevelle could run a 13.3 sec. quarter-mile at {{convert|108|mph|abbr=on}}. Chevrolet rated the engine at {{convert|425|hp|kW|0|abbr=on}}, but the [[National Hot Rod Association|NHRA]] claimed power output to be {{convert|450|hp|abbr=on}}.<ref name=copochevelle>{{cite web|url= http://musclecars.howstuffworks.com/classic-muscle-cars/1969-chevrolet-chevelle-copo-427.htm |title=1969 Chevrolet Chevelle COPO 427 |work=How Stuff Works |date=11 January 2007 |access-date=18 January 2016}}</ref> The following year, the "Chevelle SS 454" model was introduced, which used the {{convert|454|cuin|L|1|abbr=on}} [[Chevrolet big-block engine#454|Chevrolet LS6]] big-block engine rated at {{convert|450|hp|kW|0|abbr=on}}, the highest factory rating at that time.<ref>{{cite web|url= http://musclecars.howstuffworks.com/classic-muscle-cars/1970-chevrolet-chevelle-ss-454.htm |title=1970 Chevrolet Chevelle SS 454 |work=How Stuff Works |date=10 January 2007 |access-date=18 January 2016}}</ref>

The fastest muscle car produced by American Motors was the mid-sized 1970 [[AMC Rebel#The Machine|AMC Rebel "The Machine"]], which was powered by a {{convert|390|cuin|L|1|abbr=on}} engine producing {{convert|340|hp|kW|0|abbr=on}}.<ref>{{cite book |last=Cheetham |first=Craig |title=Ultimate Muscle Cars |publisher=MBI Publishing |year=2007 |pages= [https://archive.org/details/ultimatemuscleca00chee/page/12 12–15] |isbn=978-0-7603-2834-7 |url-access=registration |url= https://archive.org/details/ultimatemuscleca00chee/page/12 }}</ref> The Rebel had a 0–{{convert|60|mph|abbr=on}} time of 6.8&nbsp;seconds and a quarter-mile run in 14.4&nbsp;seconds at {{convert|99|mph|abbr=on}}.<ref name="machine">{{cite web|url= http://musclecars.howstuffworks.com/classic-muscle-cars/1970-amc-rebel-machine.htm |title=1970 AMC Rebel Machine |work=How Stuff Works |date=12 January 2007 |access-date=14 February 2022}}</ref>