There will always be the greats that everyone remembers and those that deserve way more attention than they got. Nowhere is that more true than in the world of muscle cars. We all know about how badass Challengers, Mustangs, and Camaros were. But so many alternatives that lived in their shadows have been completely forgotten about over the last few decades.What makes this even harder to believe is the fact that a lot of those lesser-known cars could go toe to toe with the biggest names in the industry. Some of them, particularly the drag-oriented models, could even beat the brakes off them in a race. As frustrating as that can be, it does make themultimate sleeper material. That said, we're happy to explore ten forgotten muscle cars that performance junkies need to know about.The muscle cars below have been selected based on quarter-mile performance according to period tests and reputable sources such as Hemmings.com and Hagerty.com. The selection was then ranked from slowest to fastest. 1978 Dodge Li'l Red Express: 360 V8 EH1 1/4 Mile: 15.7 Seconds Bring A Trailer Oh, now we're testing your patience. This one isn't a muscle car at all; it's a truck. With all due respect, the Dodge Li'l Red Express is an honorary member of the muscle car segment, just with a little extra flair. In 1978, Dodge went for broke with this entry to its Adult Toys lineup. Dodge's little red truck was decorated to match the theme of its stablemates, ending with an appearance that looked like a model you'd find under a Christmas tree.Bring A Trailer The police-spec 360 cubic-inch V8 produced a respectable 255 horsepower that got the mighty rig through the quarter mile in 15.7 seconds in a test conducted by Hot Rod in 1978, which was enough to declare it the quickest American production vehicle for that model year. Mind you, this made it faster than even the mighty Corvette, which is still hard to believe to this day. 1971 Dodge Demon: 340 V8 1/4-Mile: 14.4 Seconds Mecum The Demon name is synonymous with Mopar performance today, but it first appeared way before supercharged Hemis were standard. Dodge originally debuted the Demon nameplate in the early '70s with the 1971 Dodge Demon, effectively attaching it to a fastback Dart. Unfortunately, the name may have been just a little too much for people to handle back then, and sales numbers suffered, despite how popular the Dart itself was. Dodge ultimately renamed it the Dart Sport in 1973, shelving the name until the world was ready.MecumWith a 340 producing 275 horsepower under the hood, these little devils could clear the quarter mile in 14.4 seconds, according to Fastest Laps, which was faster than some big-block legends of the time, like the 383 Road Runner. Imagine what could be done with run-of-the-mill Day 2 upgrades that wake even the laziest V8s up. 1986 Buick Regal T-Type 1/4 Mile: 14.3 Seconds Bring A TrailerEveryone knows about the Buick Grand National and GNX. These black '80s bricks are all the rage these days, and their performance isn't taking anyone by surprise. What many don't realize, however, is that they weren't the only Regal-based whips rolling with turbocharged V6s under the hood. Buick also had the Regal T-type models, which were sold with the very same equipment the Grand Nationals were wreaking havoc with. Bring A Trailer The main difference is that they were available in boring colors, not exclusively in black. That meant what might look like Grandpa's Buick is actually producing 235 horsepower and can clear the quarter mile in 14.3 seconds, according to a Hot Rod test conducted in 1986. If you happen to find one today, they can still make a seriously great sleeper build, especially if you don't paint it black. 1971 AMC Javelin AMX: 401 V8 1/4 Mile: 14.3 Seconds Bring A Trailer The AMC Javelin AMX is among the most atrociously underrated muscle cars ever produced. These things have legendary styling, curb weights to rival go-karts, and meaty V8s under the hood. By all counts, they're exactly what gearheads dream of owning. Yet somehow, they're the last car to come to anyone's mind when the horsepower wars are brought up.Bring A Trailer The 1971 AMC Javelin AMX equipped with a 401 that was able to deliver a respectable 335 horsepower that'd put it in league with Chrysler's 383 Magnum and Ford's 428 Cobra Jet engines. It barreled down the quarter in just 14.3 seconds, according to Hagerty. It was quicker than the Road Runner of the same year with the aforementioned equipment, but it failed to stick the landing in sales. 1970 Mercury Cyclone Spoiler: 429 Cobra Jet 1/4-Mile: 13.99 Seconds Mecum Auctions Ford Fans have been screaming about the Cyclone Spoiler since this article kicked off, and for good reason. No. It's not the coolest or most attractive car in the world. It is, however, well-endowed with horsepower potential. Under the hood of this monster is the legendary 429 Cobra Jet engine.Barrett-Jackson AuctionsThe 429-cubic-inch Ford V8 is an absolute beast that was rated to deliver 370 horsepower in stock form. With it, the Mercury could complete the quarter mile in 13.99 with the optional Drag Pak, according to Hemmings. This kind of performance was more than enough to put many muscle car legends in its rearview mirror. 1973 Pontiac Firebird Trans Am: SD-455 1/4-Mile: 13.5 Seconds Mecum When you think of dominant muscle cars, you don't think of anything with the year 1973 attached to it. By then, engines were being choked down due to the onset of the oil crisis and emissions era, and the performance segment was a mere husk of its former self. The 1973 Pontiac Firebird Trans Am equipped with a Super Duty 455 was the exception.Mecum Auctions These Firebirds were rated to produce 290 net horsepower. While lower than you'd expect, consider this isn't a gross horsepower rating like you'd see attached to earlier years. It was more than enough to get the job done, hurling the Pontiac through the quarter mile in 13.5 seconds, according to Hot Rod, better than even some Mustangs of the same year, like the 351 or 302 Windsors. Despite being a bona fide missile on wheels, only about 4,000 Trans Ams were sold this year, with overall Firebird Sales being a fraction of the Camaros, its slower counterpart. 1970 Buick GSX Stage 1: 455 V8 1/4-Mile: 13.4 Seconds via Bring a TrailerThe Buick GSX Stage 1 is everyone's favorite forgotten muscle car. This mad machine famously touted itself as the "Hemi Killer," poised to compete alongside the biggest and baddest machines of the day. Buick conservatively rated the Stage 1 GSX to produce 360 horsepower and 510 lb-ft of torque.Kuyoth's Klassics Though the horsepower fell short of the 426's rating, it ultimately delivered performance to keep owners' egos in check. In stock trim, most sources agree the Buick GSX could clear the quarter-mile in 13.4 seconds, which was better than most in the height of the horsepower wars. Unfortunately, it failed to set the world on fire and lived on in the background. 1964 Ford Fairlane Thunderbolt: 427 FE 1/4-Mile: 11.8 Seconds MecumThe Ford Mustang soaks up all of the attention at the Blue Oval. Whatever's left over typically flows to the Ford Torino. Little did you know, the Ford Fairlane was the gnarliest of the lineup before they arrived. More specifically, the Fairlane Thunderbolt was set up to shut Chevrolet and Mopar down.Mecum By the time Ford got done throwing out whatever wasn't needed and swapping in fiberglass panels, the car weighed just 3,200 pounds. With the 427 under the hood that produced 430 horsepower, these factory lightweights were able to clear the quarter-mile in just 11.8 seconds. However, these are known to be much, much quicker. 1965 Dodge / Plymouth A990: 426 Hemi 1/4-Mile: 11.18 Seconds MecumUnless you're a Mopar nut, you might never have heard of the A990 cars. These were factory lightweights that Chrysler engineers dreamed up in an attempt to achieve quarter-mile dominance. The short version is that anything that didn't need to go for a ride didn't, and lightweight versions of every part possible were used. They then crammed a 426 race Hemi under the hood. While the A990s were rated to produce 425 horsepower, anyone who knows anything about these motors will tell you they made way more. The A990 Plymouths and Dodges could clear the quarter in 11.18 seconds from the factory, according to Dodge. That said, these are often credited as being the factory-optioned cars to break the 10-second barrier, which vary-well may make them the fastest cars on this list. 1963 Chevrolet Impala Z11: 427 V8 1/4-Mile: 10.8 Seconds MecumMost of us think of the late 1960s to the early 1970s when the horsepower wars are discussed. The 1963 Chevrolet Impala Z11 was an extremely potent factory lightweight that ended the war before it could start. These drag missiles were stripped down and outfitted with absolutely menacing torque mills.Mecum The 427 cubic-inch V8s under the hood were rated to produce 430 horsepower. The ability to clear the quarter-mile in 10.8 seconds suggests that number might be a little low. These were also the first stock body cars to break the 120 mph barrier in the quarter, setting a very high bar that legends from later years would fail to meet.Sources: Fastest Laps, TopSpeed, Hagerty, Hemmings, Hot Rod