It’s nice that the Dodge Challenger’s reputation rests on two generations far removed from each other in time, yet both loved about equally (before anyone says it, I know that the Mitsubishi-based Challenger of 1978-83 has its fans, too). Still, there’s nothing like a muscle-bound ponycar from the early 1970s, and although this particular Challenger started life with a 318, it now has a rebuilt 340 under the hood. No Challenger is going to be a sleeper, but without the scoops and stripes that many examples have sprouted over the years, it talks somewhat more softly, at least until you turn the key. Brisk bidding on eBay has taken this convertible to $29,680 with a week to go on the auction, and if you’re looking to drive your new prize home, it’s located in Pompano Beach, Florida.
The fender tag will come with the car, although for some reason, it was not reattached after being removed for a paint job, I assume. It reaffirms that the Challenger originally came with a 230-horsepower 318 and a TorqueFlite 904 automatic, in addition to B5 Blue paint (also known as “Brite Blue”). The car has been repainted at some point in a darker B7 Blue (the aptly named “Dark Blue”).
While the original 318 will come with the car, it has been replaced with a “strong rebuilt 340 engine” and matching transmission (we’ll assume it’s a 727 TorqueFlite). No details on the build are given, but a factory 340 was rated at 275 horsepower, although that was notoriously conservative; the NHRA refactored it almost immediately at over 300 horsepower. Also notice that there are no power brakes, although the seller points out that the front brakes are discs. Additionally, the differential has been upgraded to an 8 3/4″ unit with 3.55:1 gears. Judging by the air conditioning equipment on the passenger inner fender and firewall, this car came from the factory with air (I think there’s an “H51” on the fender tag, but it’s obscured by a shadow, and the dashboard controls are correct for an air-conditioned car). The compressor is in the trunk with some other original parts.
The interior shots are all a little darker than I’d like to see; it’s hard to determine the condition, although nothing stands out as being alarming. It does have a console and a floor shifter (although I can’t quite see the shifter itself).
Here’s the trunkful of parts, including the aforementioned AC compressor and original air cleaner.
The 1970-74 Challenger still looks just right, and with only 2,165 1971 convertibles built in the final year of production for that body style, it’s a fairly uncommon car. Even though this one isn’t exactly factory stock, it is going to be a little more fun with that giant-killer 340 under the hood and deep gears out back; besides, who wouldn’t want to drop the power top and listen to that small-block rumble?
I had a 1960 Valiant with 3.55 gears, but folks, that was a 170 slant six. I really doubt a 340 would need that. Just going to make the freeway noise a screaming nightmare. I admit the combo would be fun, at least around town. The writer hints at that as he calls it a sleeper. Only useful for foolish street light antics. Just think of the cowl shake on take offs. The 318 was the best engine here. A convertible is not for street mischief, it is for quiet cruising in the sunny country side. / Despite popular opinion, I think the 71s were pretty sharp, better than the 70s in both front and rear.
318 being the best engine ??? Huh ? In what world would that be ? And 3.55-3.70 would be the perfect gear for a hopped up street cruiser, 3.90,s would be perfect for me, even without an OD Trans, i daily drove 3.91,s for years, Hi Way too, not that bad, can always go little taller on rear tire to compensate. I also noticed in your other comment that you said getting pinned to the seat will get old ? I still don’t understand how that’ll ever get old ! Unless your just too old yourself ??? Foolish street light antics and cowl shake from Low gear ratio ??? I’m still trying to understand that one.
Nice car, great engine choice, a 4spd would be more fun. It will be expensive, for good reason. Drive it as it sits, no reason to muck with it.
Steve R
That 340 is probably from a 72 or 73. Not the proper air cleaner from a 70 or 71. I do like this one better, though, much sharper looking. 72s got detuned to use unleaded gas, less HP, though a rebuild would probably make up for that, if HP is what you want. I think the original 318 could have been rebuilt. Bore it out for new pistons, a slightly warmer cam, small 4bbl, dual exhausts with an H cross tunnel. More HP, but smoother running. Plus, numbers matching on a somewhat rare car, plus you could have used the original trans. Same for the rear end. As I noted above, I feel 3.55 is geared way too low for regular enjoyable driving. What did a 318 auto come standard with, 2.94 maybe? 3.23 I think was optional on the auto, but standard with a standard trans. I would go no lower then that. I have driven some performance cars with 4.11 gears. Almost undriveable on a super highway, fine for the track. Throw you back in the seat, but that gets old, plus, really not all that safe as you can loose control of the car. Still, a really interesting car in a beautiful color. Nice to see the standard hood once in a while. Back when new, more cars had those then you see today. Nothing wrong with the optional sport hood, good looking as well, but nice to see what many of us remember as more common. Could it really be more then 50 years ago? How old am I?
A matching numbers, fully restored ’71 Challenger convertible with a 318 sold at Barrett Jackson a few weeks ago for $100K or so. That’s how rare 71 convertiv bles are. Maybe time to rethink that 340? Especially when you can put a lot of invisible performance enhancements into a 318 these days (watch Uncle Tony videos).
With a convertible Hemi ‘Cuda bringing 3.3 million dollars last week, I think the tide is riding for all convertibles of that era. Entry level ones like this are going to become hard to find.
I drive a 340 Duster with 3:91’s. That is the perfect gear for street strip. I don’t think anyone takes these on long trips anymore, so 3:23 or 3:56 highway gears aren’t necessary. Might as well take advantage of the instant holeshot if you are going to drive one.
Plus cars are driving so fast (80 is the new 55) and these old cars don’t like those speeds anyways. There is a lot of road and wind noise, especially with a convertible!!! 60 is more comfortable and I don’t want to get anywhere fast as the drive is the point.
looks like a half assed craigslist rebuild under the hood. 1/2 the parts look like they are still in the trunk for you to finish. the bids right now are just plain crazy with days to go and reserve not met. i guess i am just old and don’t get where this people are bidding from because it surely is not with their head.
Ah, the fender tag will come with the car, although for some reason, it was not reattached after being removed for a paint job? Is this a red flag for anyone?
No red flag here.
The only difference between a 318 and a 340 is the bore (3.906 inches versus 4.04 inches), so if the engine was rebuilt, it could simply have been bored out and fresh pistons fitted, to bump the displacement up to 340 cubic inches. A check of the VIN number stamped into the block will confirm if the block is original to the car or not. The block would have to have been bored out by 0.134 inches, so it’s not a simple job, but for a good machine shop, not that complicated, either.
Going all of the way to 360 cubic inches requires a “stroker” crank, so it’s more money, as there’s the cost of a new crank, new pistons and new connecting rods to add to the cost.
Although the architecture is the same a 318 block doesn’t have the meat to bore to 4.04″. The castings are not the same. The blocks have ‘318’ or ‘340’ cast right into the side. I’ve never tried it personally, but the conventional wisdom is that it’s a no go.
I think it looks decent enough with the bucket seats but you are right need better quality pictures of the interior. If you have ever driven any thing with a 340 such as a duster you know how fast they are. I can feel the power still and still remember the really nice sound coming from the 340. I only hope that this challenger handles better that the duster that my father had. Once you get the rear wheels breaking lose on a corner I found it was hard to keep the rear end from coming around on you. I could steer out of anything with my Camaro but it wasn’t as fast as the Duster and handled better.
Too bad the price is going to be insane. Keeps an old guy like me from enjoying a 340 again.
Everyone has been conditioned to think that their engine is going to fly apart if they drive more than a few miles at 3000 rpm or more. I still to this day drive 3.55 geared Challenger convertible and my 4.10 geared van both without overdrive on the interstate on 100 plus mile trips. Keep em simple.
I’m with you, Mike. I drive my fleet on the freeway regularly, and although most of them have taller gears, they all turn 3000-3500 or so at those speeds.
Bid to $49,100 on 2/7/2026 but did meet reserve.
Steve R