A 1971 PlymouthHemi GTX is already rare enough to make Mopar people speak in hushed voices, but this one pushes the whole thing into museum-with-a-bidding-number territory. Crossing the block at Mecum Indy 2026 on Friday, May 15, this Winchester Gray bruiser packs the 426/425 HP Hemi V8, a 4-speed manual, and the kind of production story that turns a big Plymouth into a certified auction-room event. Only 11 Hemi GTXs were built for 1971 with the 4-speed, and this car is said to be one of just four with the A34 Super Track Pak, 4.10 gears, and Sure Grip. More than anything, that’s Mopar lottery math. Plymouth Built This GTX Right At The End Of The Hemi Party MecumBy 1971, the muscle car world was already feeling the squeeze. Insurance costs were rising, emissions rules were getting tighter, and the wildest street cars from Detroit were living on borrowed time. Plymouth still offered the GTX as its upscale muscle machine, but the days of casually ordering a street Hemi were almost over.That makes this car’s 426 cubic-inch Hemi the main event. Rated at 425 hp, it was the same kind of big-lung V8 that had built Chrysler’s reputation in drag racing and on the street. In a GTX with a 4-speed manual, it turned the car into a very expensive, very serious tool for people who knew exactly what they were ordering.The A34 Super Track Pak adds another layer. With 4.10 gears and Sure Grip, this was built to leave hard, pull hard, and make every fuel stop feel like a small financial implosion. This Winchester Gray GTX Has The Paperwork And The Good Stuff MecumIt's a pretty keen point to note: it still has its original broadcast sheet and window sticker. That's cool because with a car this rare, every option and production claim carries serious weight once the bidding starts. Matching-numbers Hemi, and matching-numbers 4-speed: both are here.The spec sheet reads like someone checked the fun boxes and then kept going. Power steering, power disc brakes, Air Grabber hood, bucket seats, center console, Rallye wheels, and Goodyear Polyglas tires all land on the list. The exterior is Winchester Gray, the interior is black, and that combination gives the car a much meaner attitude than a brighter high-impact color would.There's also the fact that this is believed to be the only 1971 Hemi GTX finished in Winchester Gray. “Believed” is doing careful legal work there, but even without that claim, this is still one of 11 4-speed Hemi GTXs from 1971. Plenty to lean on there. The Kind Of Mopar That Makes Auctions Weird MecumThe car's also received a comprehensive rotisserie restoration completed by Dennis Kohr, which should help it land in that sweet spot between showpiece and factory-correct muscle car artifact. The GTX was already Plymouth’s more grown-up muscle car, but with a Hemi, 4-speed, and Super Track Pak, it becomes something far angrier. Silent Screamer MecumThere’s also a funny little contradiction baked into cars like this. They were built as street weapons, but today their rarity almost makes them too valuable to use that way. A 4.10-geared Hemi GTX wants noise, rpm, and a wide-open road. A one-of-11 production figure wants climate control, careful hands, and insurance paperwork thick enough to stop a small-caliber round.Undoubtedly, this Plymouth should get attention at Indy. It’s not the loudest-colored Mopar, and it doesn’t need to be. A Winchester Gray 1971 Hemi GTX with four pedals, the right rear axle, and factory paperwork is the sort of car that lets the spec sheet do the shouting.Source: Mecum.