Dodge and Plymouth muscle cars from the classic era are some of, if not the most collectible, rides today, and there are very good reasons for that reality. First, Golden Age Mopars are simply the coolest things to ever hit the streets, with nothing matching the brutal beauty of a second-gen Charger or sheer aggression of a Hemi 'Cuda. Next, equipped with the most powerful V-8s of the day, nothing could beat a Mopar off the line, and finally, these cars are exceedingly rare. GM and Ford cranked out millions of muscle cars in the classic era, while Chrysler Corp. rides were more modestly produced, especially with an era-defining 426ci Hemi V-8.Collectors have certainly elevated classic Mopars to elite status, pushing them into the same conversation as rare Corvettes or even European sports cars. Some choice rides, like the '69 Charger Daytona and '71 Hemi 'Cuda Convertible, are now multi-million-dollar auction killers, and there are several others that are close behind. That value is, of course, mostly tied to a car being equipped with a numbers-matching 426 Street Hemi, which, due to its rarity, is a price multiplier. Hemi cars are beyond most people's budgets, but there is an incredible Mopar with a 440 Six-Pack, which is almost as killer and almost as rare, that collectors have forgotten about, and which offers classic muscle car perfection at a more doable price. 1971 Plymouth Road Runner 440+6 Emergent B-Body Mecum In 1971, Chrysler's B-Body platform got a major overhaul with a completely wicked and criminally underappreciated "fuselage" body style. The once-boxy Road Runner was suddenly an aerodynamic street assassin that still conveyed the muscular stance of the original budget muscle car. While popular at the time, for whatever reason, enthusiasts never really fell in love with the new B-Body style, and for the longest time, third-gen Chargers and second-gen Road Runners weren't considered all that collectible. With how cool these Mopars look, it's hard to understand why, and '71 was still a good year for performance, but they were largely ignored by collectors.That's beginning to change with some Hemi-equipped '71s going in the half-million range, but the 440 Six-Pack/6BBL cars are still flying under the radar, offering some killer classic value. A 1971 Road Runner 440+6, which, for the uninitiated, is equipped with a 440ci V-8 and three two-barrel carburetor setup, can be found for as little as $50,000 for a running and driving example. We'll touch on the value of this forgotten ride in more detail soon, but it's an astounding discount from a '71 Road Runner Hemi, one of which recently sold for $500,000. A Hemi isn't ten times more powerful than 440+6, and in fact, they offer similar performance, but the price sure as heck is. The Elusive 440 6-Barrel MecumChrysler introduced a new version of their 440ci V-8 in 1969 with three two-barrel Holley carburetors on a high-rise intake, which offered Hemi-like performance at a fraction of the cost. Known as the "Six-Pack" for Dodge cars and the "6-Barrel" for Plymouth rides, this wondermill produced 390 horsepower and 490 pound-feet of torque, which wasn't far off the 426 Hemi V-8's 425 HP/ 490 LB-FT output.In 1971, Plymouth began badging cars equipped with it as "440+6" when previously they had been branded "6BBL." 9,761 Street Hemi V-8s and another 734 Race Hemis were produced between 1966 and 1971, making it a rare and awesome engine, but the 440 Six-Pack/6-Barrel is almost as elusive. From 1969 to 1971, only 13,883 were built, with 6,063 going to Dodge muscle cars and 7,820 gracing Plymouths. The Rarest Of Small Batch Road Runners Mecum With Dodge superstars like the Charger and Challenger, most people don't realize how popular the Road Runner was, but it reigned as Plymouth's best-selling muscle car of the Golden Age, far eclipsing the Barracuda. Moving 44,599 units in its '68 debut, the Road Runner hit a high of 84,420 in '69, but by '71 it was almost an afterthought.With just 14,218 units produced in 1971, the Road Runner suddenly became the worst-selling Mopar, falling far behind the 46,183 units of its B-Body cousin, the Dodge Charger. The '71 Road Runner gets even rarer with the 440+6 cars of which only 246 were made.Conventional wisdom would say that something as amazing and powerful as a '71 Road Runner 440+6, built in extremely limited numbers, should be a big-money collectible, but so far that is not the case. ’71 Road Runner 440+6 Prices And Values Mecum According to J.D. Power, which bases its values on real-world sales, a 1971 Plymouth Road Runner 440+6 sells for, on average, $58,000, which is a steal for such a killer classic. Hagerty, whose prices are a little more speculative, has a good condition value for this overlooked Mopar a little steeper at $88,100, but that still ain't bad for something this awesome.Bring a Trailer, on the other hand, recently sold a completely restored '71 440+6 for just $50,000, but there is a catch as it is not a numbers-matching car. Originally equipped with a 383, during the restoration process, a 440 Six-Pack was dropped in, but for that price, who cares? If purchased for an investment, this one falls short, but if the buyer wanted a weekend adult toy for fun and attention, it was a total score. 440 440+6 Vs. 426 Hemi Auction Price Battle Mecum As we touched on earlier, the presence of a 426 Street Hemi in a Mopar multiplies its value exponentially, and the same is true for the oft-overlooked 1971 Road Runner. With 55 produced, '71 Road Runner Hemis are among the rarest Mopars, and that means they sell for a premium. These rarities generally top $200k at auction, but an exquisite one blew up Mecum Indy 2023, crossing the block at a cool half-million. '71 440+6 cars, on the other hand, go for considerably less, and really, there's not a lot of action on them at the big auction houses.Bring a Trailer seems to be the best source for a '71 440+6, but many of them stall at around $50,000 and don't hit the reserve. That, in a way, is an indication of their value, because if that's all people are willing to pay, that's what they are worth. There was one 440+6 on BaT that sold for $97,500 in 2023, so there is hope for this tragically slept-on Mopar growing into a genuine classic collector car. Don’t Forget The GTX Mecum The Plymouth GTX was the upscale version of the Road Runner that was billed as the "gentleman's muscle car." In '71, it was almost the exact same thing as the Road Runner, only loaded with more features, and suffered the same fate as an overlooked Mopar classic.A '71 440+6 is actually worth $3,800 less than a Road Runner with a J.D. Power average retail price of $54,200, while Hagerty has it slightly more valuable with a $90,000 good condition rating. Bring a Trailer sold a numbers-matching GTX 440+6 in 2020 for the shockingly low price of $47,690, but another went at Mecum Kissimmee 2021 for $99,000, so there is a wide range on this one, but it certainly offers an attractive and affordable alternative to a Hemi car. How Fast The Road Runner 6-Barrel Can Run Bring a Trailer There are several magazine road tests from the late 1960s that have Six-Pack cars running quarter-mile ETs in the low-13s and even a few that have them quicker than the Hemi. In 1971, the 440 Six-Pack/6-Barrel lost 5 ponies for a 385 horsepower rating, while the 426 Hemi didn't skip a beat, so there was no challenge that year from the budget V-8.That being said, the '71 Road Runner 440+6 was still a force on the street with a 5.4-second 0-60 time and an impressive 13.7-second quarter-mile ET. The '71 Road Runner Hemi was still a low-13-second car, but the 440+6 could definitely hang with it, and depending on the drivers, could still take a red light challenge from its more expensive V-8 sibling. Chevelle SS Slayer Bring a Trailer In 1970, the pure muscle car rivalry, with no pony cars invited to the brawl, was between the Plymouth Road Runner Hemi and the Chreolet Chevelle SS 454 LS6. Our sister site, TopSpeed ran an epic fictional drag race between these two titans to determine the king of the streets, and the Plymouth edged the Chevy by four-one hundredths of a second with a 13.4-second quarter-mile.By 1971, things had changed a lot, with the LS6 being discontinued and the 454 V-8 dropping from 450 horsepower to just 365 ponies. It wouldn't be fair to run the '71 Chevelle SS against a Hemi, which was still as potent as ever, so the Road Runner 440+6 became its closest competitor. In reality, there was nothing close about this competition, with the '71 SS lumbering to a 14.5-second quarter-mile, almost a full second slower than the 440+6. Class Of ’71 Road Runner 6BBL Mecum Dodge Challenger Hemi R/Ts and Plymouth Hemi 'Cudas have always been primo rides, but for far too long, collectors dismissed the 1971 Chrysler B-Bodies. That has been rectified with a '71 Charger Hemi R/T fetching $352,000 at auction and the aforementioned half-million dollar Road Runner Hemi, but the 440+6 is still woefully underappreciated.A 13-second classic Mopar with arguably the hottest design, which was produced in limited numbers, should be a collector's dream. Instead, it's a bargain collector's dream, which isn't necessarily a bad thing. People of normal means can acquire this Mopar classic, while the Hemi cars are now just for tech billionaires and OPEC oil sheiks. As an added bonus, the 440+6 can actually be enjoyed, because there's a pretty good chance that anyone with a big-money Hemi doesn't want to risk devaluing it by putting any more miles on the odometer.Sources: Bring a Trailer, Hagerty, J.D. Power, Mecum