Dodge Demon 1971 in B5 Blue Paint & 340 Engine

Dodge only sold the Demon for two model years before quietly retiring the name, and only a fraction of those cars left the factory with the 340 small-block. This B5 Blue example is one of them — a budget compact that was hiding a genuinely serious mechanical package under a cartoon devil decal. Here is what made the Demon 340 the sleeper Mopar nobody took seriously in 1971, and why collectors take it very seriously now.

B5 Blue has a way of stopping Mopar fans mid-scroll, and pairing it with the bark of a 340 small-block is the sort of combination that turns a casual glance into a twenty-minute argument about production numbers. What most people miss is that this car was never supposed to be a hero. Dodge built it to be cheap. It sat at the bottom of the showroom, aimed at buyers who could not stretch to a Charger, and it wore a cartoon devil on the fender to make sure nobody mistook it for a serious machine. So how did the cheapest performance Dodge of 1971 end up being one of the harder ones to find today?

A Duster in a Dodge Suit

The Demon arrived for 1971 as Dodge’s version of a car Plymouth had already been selling with great success. Plymouth had taken the Valiant, given it a fastback roofline and a shorter 108-inch wheelbase, and called it the Duster. It sold in enormous numbers. Dodge dealers, watching that happen, asked for their own. What they got was the Demon, built on the same shortened A-body platform and sharing the Duster’s basic architecture, restyled just enough at the nose and tail to look like a Dodge rather than a rebadge. It slotted alongside the Dart Swinger rather than replacing it, which is part of why the model-year production split gets confusing.

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The Small-Block That Punched Far Above Its Price

The engine is what separates a Demon from a Demon 340. The base cars came with slant sixes and small V8s aimed squarely at commuters. Tick the 340 box and you got a 275-horsepower, 340 lb-ft V8 that had already earned a reputation as one of the best-balanced engines Chrysler ever built. It used a shot-peened forged steel crankshaft, a double roller timing chain, high-flow cylinder heads and a single four-barrel Carter carburetor. It made its power high in the rev range rather than in one enormous shove off idle, which is exactly why it worked so well in a light car that did not have the mass to absorb big-block torque.

Chassis Hardware You Did Not Expect on an Economy Car

The supporting hardware is the part that surprises people who assume this was just an engine swap on a grocery-getter. Demon 340s came with the Rallye suspension package: heavy-duty torsion bars up front, oversized shocks, and an anti-sway bar out back. Behind the engine sat a Sure-Grip limited-slip differential, and the whole thing rolled on wide Polyglas GT tires. Chrysler did not simply drop a hot V8 into an economy shell and hope for the best. It built a coherent car, and the result handled noticeably better than the heavier B-body Mopars that got all the magazine covers.

How Few Were Actually Built

Production numbers explain the rarity. For 1971, Dodge built 10,098 Demon 340s. Against that, the base Demon accounted for 69,861 cars and the Dart Swinger another 102,480. So the 340 version made up under six percent of the Demon run and a far smaller slice of Dodge’s compact output overall. At the time that ratio simply reflected what buyers wanted, which was cheap transportation. Fifty years later it is the reason a genuine 340 car with matching numbers is worth several times what a base Demon brings.

The Name That Got Dodge in Trouble

The nameplate itself did not survive long, and not for mechanical reasons. The Demon badge, complete with its pitchfork-wielding cartoon character, drew objections from religious groups almost immediately. Dodge kept it for 1971 and 1972 and then dropped it, renaming the car the Dart Sport for 1973. That two-year window is unusually short for a Detroit nameplate and it is the single biggest reason Demons feel scarcer than their sales figures suggest. Dodge would not touch the name again for more than four decades, until the 2018 Challenger SRT Demon made it a halo badge instead of an economy-car joke.

1972 and the Numbers That Changed Overnight

Anything built after 1971 needs a footnote on the horsepower. For 1972 the industry moved from gross to SAE net ratings, measuring output with accessories and exhaust attached rather than on a bare engine stand, and compression came down at the same time. The 340 that read 275 horsepower in 1971 read 240 in 1972. The engine had not been gutted, but the number on the brochure fell hard, and that shift is why cross-year comparisons of muscle-era horsepower figures are so often misleading. A 1971 Demon 340 sits on the last side of that line where the big numbers were still being printed.

What Buyers Should Look For Today

If you are shopping, the A-body’s weak points are well documented and worth knowing before money changes hands. Rear frame rails, trunk floors, the area around the rear window and the lower quarters all trap moisture, and a repainted car can hide a great deal. Verify the engine is the 340 the seller claims rather than a later 360 wearing the right valve covers, because correct blocks have become genuinely expensive. Check the fender tag and broadcast sheet against the paint, and be honest with yourself about how much of the car is original versus how much has been assembled from other cars over the last fifty years. On an A-body that has passed through many hands, that answer is rarely simple.

Why B5 Blue Keeps Showing Up in the Comments

The color is not incidental to any of this. B5 Blue was a standard Chrysler code rather than one of the High Impact shades, which meant it did not carry the extra cost of Plum Crazy or Go Mango and it did not shout the way those colors did. On a Demon, that understatement is exactly the point. The car already looked like an economy compact, and a conservative metallic blue completed the disguise right up until someone opened the throttle. It also happens to suit the body’s proportions unusually well, hiding the slab-sidedness that brighter colors tend to emphasize. That combination of restraint and capability is why B5 Blue cars generate the reaction they do whenever one turns up at a show, and why so many restorers choose it even when the original tag says otherwise.

What a Documented 340 Car Is Worth Now

As for what all of this is worth, the market has been consistent for a while now. Base Demons and Dart Swingers remain among the most affordable ways into a genuine muscle-era Mopar, which is part of their appeal. A verified 340 car with matching numbers, correct Rallye suspension components and paperwork sits in a completely different bracket, and a four-speed example higher still. The gap between the two is wide enough that clones are common and honest sellers will volunteer their documentation before you ask. That is the real reason cars like this one matter: not because a 275-horsepower compact was ever the fastest thing Dodge sold, but because so few people wanted one at the time that finding an honest survivor now takes genuine effort. Share your thoughts on this one in the comments below.

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