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Slant Six Project: 1970 Dodge Challenger Convertible

With the fine selection of V8 engines available for the 1970 Dodge Challenger, it’s easy to forget that the entry-level powerplant was a Slant 6 of the 225 cubic inch variety, making 145 horsepower with a one-barrel carburetor.  Oddly, that’s one of the things I find alluring about this Mopar convertible, that nobody’s switched that out yet and the car remains true to its heritage, although the next owner may see things differently.  This E-Body project is located in Columbus, Ohio, and can be spotted here on eBay, where no one has placed the opening bid of $25,000 yet.  Another option is owning it right now for the buy-it-now price of $28,000.

There’s a different story outside, as the flat factory hood has been swapped out with a rally component and its matching fenders, but if you want to put the body back to factory specs the original 3 pieces are also included in the sale.  The lead photo is the only picture we get that shows a view of the entire car and the rest are close-ups of various areas, but it’s clear that the quarters have fallen victim to the tin worm and will need to be replaced.  Some good news is the fender tag is still present, documenting such details as Banana Yellow (FY1) was indeed the color the Challenger was wearing when it left Hamtramck.

Most of the interior appears to be complete, but it could use a good refreshing plus a fresh Slap Stick shifter handle sure would look cool sticking up out of the console, that is unless you want to leave everything as it came.  The seller thinks a wet carpet is what caused the floors to corrode, and the fabric must have been saturated for quite some time to cause this kind of deterioration but some replacement floor metal also comes with the Challenger.

I get that the Slant Six isn’t exactly a preferred engine to find under the hood, but to locate a Challenger that hasn’t already been transformed into something different is just sort of refreshing.  The car is said to run and stop, and that’s about the extent we get regarding the drivetrain.  On the other hand, I understand that this one’s ripe for a V8 of your choice, and a 340 seems like an excellent idea here unless a big block is more to your liking.  What directions would you head in when restoring this 1970 Dodge Challenger Convertible?


  1. HoA Howard A Member

    I’m sure the salespeople sat around the water cooler and laughed about this one. Here you have probably THE most sought after car, a ’70 Challenger ragtop, with probably the least attractive motor. I read, Chrysler sold 77,000 Challengers in 1970, only about 3800 were ragtops, and even more amazing, only about 378 got the car with a 6, making this car, one of the rarest Challengers made in 1970. I’m not sure what will happen to this car, the seller clearly knows what they have. Whether the person THEY got it from knew that, but with hemi ragtops( 9 known to exist) bringing 6 figures, I wonder what is more valuable for the future? Quite a find.

    Like 20
    • Robert Amoroso

      1971 is the year only 7-9 Hemi convertibles were produced.

      Like 0
      • Robert Amoroso

        Sorry, that was for Hemi ‘Cuda convertables.

        Like 1
      • JoeNYWF64

        I wonder how many ’69 camaros were RSs with the 230 or 250 strait 6.
        Incredibly, i have never seen even 1 hardtop in the flesh with that body/engine combo!

        Like 0
  2. bobhess bobhess Member

    Some structural rust underneath tells me this car needs quite a bit of money and time put into it. Having all those spare parts will certainly help with that. I have seen cars with modified slant 6 engines that do wonders for power without taking away driveability. Dual carbs and exhaust, cams, etc. I wouldn’t put a V8 in it as it is a rare bird as it sits.

    Like 26
    • St.Michael

      HYPER-PAK…4bbl or EFI duals on the /6 with a turbo

      Like 12
      • Roland Schoenke

        That’s what I was thinking, the hyper pack is cool and would certainly start more conversations at a car show

        Like 0
    • Robert Amoroso

      Hey Bob, here’s another project for you. Right up your alley. Hyper pac slant six made over 300 hp in a 225 in early ’60’s.

      Like 9
      • GOM

        I agree wholeheartedly. A few mod’s to the slant 6 would make this an excellent touring vehicle or weekend plaything. Even stock, they were no slouch. Not everyone wants a 6 MPG road rocket, and likely the lighter 6 would make this car faster in the esses than a 426 or 440. I’d have more fun corner-carving on secondary roads than I would doing burnouts and straight line street racing. To each his own, I guess, but I hope this relatively rare bird is restored as-is to six-in-a-row glory!

        Like 10
  3. Bill Schopf

    “Save” the drive line! (Motor, transmission, driveshaft, and rear end.) Install a late model 5.7 Hemi, 6-speed with pistol grip shifter, aftermarket driveshaft, and Dana 60 rear end.
    After it’s moving on it’s own, enjoy it. Upgrade the brakes. Work on one quarter at a time so you can check gaps from the other original sides measurements. Eventually paint it. They do look cool in black “hot rod” paint.

    Like 3
    • Wade Pierce

      I bet someone got that car cheap as Howard stated, but a Slant 6 Challenger Vert is a RARE BIRD INDEED! Anyone who would butcher this car by installing a V8 JUST KILLED any Collector value left in it, imo…Restore it like it sits and you’ll have one of the few Top Banana, if not the Only, Yeller Slant 6 Convertibles left… 🤔 Don’t recall seeing a Challenger 6, but there was that ’68 or 9 Charger with one in it, in GA, a few weeks ago and it too was Rare as far as those left runnin a 6 banger. HOPE this goes to someone who appreciates the rarity as well as the gas saving this Top Banana Challenger Vert presents. Glws

      Like 13
      • Wade Pierce

        Also forgot to add, banana yellow rules! Glws huh

        Like 0
      • HoA Howard A Member

        You know what would be fun, Wade, dress the outside in “hemi” attire, badges, hood callouts, the whole magila, then open the hood, BURN!!!

        Like 8
  4. St.Michael

    HYPER-PAK…4bbl or EFI duals on the /6 with a turbo

    Like 2
  5. JohnfromSC

    It’s going to take $20K to rebuilt the body and $5K or more to fix dash and interior. Then paint. That’s not including rebuilding brakes, suspension or paint. You are likely invested $50K plus price of car without even any drivetrain work.

    The bottom line is that no one will invest that much to keep this orlginal. At BJ last week, restomods ruled. Cars that I estimate cost $125K to build were routinely selling for $300K. Even a 63 split window vette ( other than a big tank fuelie) which sells for $150K is bringing $300K as a resto.

    And this is opinion is from someone who owns multiple cars ranging from 1940-1970, all restored to a highly original level.

    Like 8
    • nhcarnut

      Back in 87 I had a 68 Charger with a 225 slant 6 with a 3 on the tree . I really enjoyed that car .

      Like 2
      • stillrunners stillrunners Member

        A lady nieghbor had one as well – a white 1968…..tried to buy it off the kids but that was nooo way.

        Like 1
  6. geezerglide 85

    New this was probably a secretary’s car, vert, slant 6, automatic, bright yellow, but dad approved. A lot of Mustangs and Camaros made this way, but not too many Mopars. I’m sure if you ran the numbers it is a very rare car indeed. BUT this one needs just about everything. I know I’m old and cheap, but I just don’t see 28 grand here. I think the 6 cyl. Javelin is a better deal

    Like 11
  7. Danno

    You’ll never go wrong with a Slant 6… or quick.
    This car is beautiful with the mechanicals it came with. If I was fixing the car, I’d leave the powertrain as is, rebuild to stock, drive it tenderly.

    Like 8
  8. Mark K

    A ’70 Top Banana Challenger Convertible with a slant six… If there ever was a cause for it, we need Sam Kinnison screaming Nooooooooo!!!

    At least it doesn’t have a three on the tree – if that even was an option…

    Like 4
  9. timothy r herrod

    In 1979 I took the brake and clutch pedals out of a 70 /6 3 speed challenger for my brothers 72 challenger that he was converting from an automatic to a 4 speed. Only /6 car I ever remember seeing.

    Like 5
    • Danno

      I like that! Excellent wordsmithing.

      Like 7
  10. Chris Cornetto

    Several sixes came through the yard in the 80s, no convertibles. There was a red coupe with a six and four on the floor with factory ac. To me that one should have not been scraped. My convertible is yellow but was a 318 and is now ofcourse a 440 which it has been for decades. I would leave this as is. I personally think the leaning tower of power is a wonderful engine. K frame is six only, so lots of changing to do here.

    Like 3
  11. Jakespeed

    Add a TorqueStorm centrifugal supercharger, blowing through an Edelbrock AVS2 carburetor through an AussieSpeed long runner intake and out through either headers or Dutra Duals and a Gill Welding FatPipe Exhaust into a TTI single 3” exhaust with a DynoMax muffler.

    Back it with a wide ratio gear set and shift kit for the little 904 Torqueflite.

    Like 4
  12. Carbuzzard Member

    Keep the six.

    Of course, I’m a preservationist, and by education and historian. Swap in a V-8 and you have just another engine-swap V8. At least to me.

    It’s not my car, however, and I suppose that “value” rules, but you know, this is one of the few you’ll ever see, if you indeed see another. But I’m not going to buy it, but if I were still writing about cars, I would write about this car. I wouldn’t write about a car that somebody plunked a V-8 into. I mean, so white?

    Like 2
    • George Mattar

      Well, look at it this way. At least no one tried to make it a Hemi clone. I had a slant six in a 63 Savoy in the mid 70s. Drove it every day, snow, rain, 95 degrees. I was bringing home $100 a week. Ran waste oil in it. Adjusted the valves once and ran $20 retreads on it. Took it with 5 passengers to numerous concerts at MSG in NY. Drove it back forth, 500 mile round trip, to PSU where I went to college. Paid $100 for it and sold it for $100 in 1979. You can have your gas sucking 440s. This car is rare. Sometimes cars are rare for what they DON’T have. Like a friend’s 65 Corvette with no radio and heat delete. Dash is bare. No heater core to leak, like the one leaking in my 73 Corvette.

      Like 1
  13. PRA4SNW PRA4SNW Member

    For a .70 Convertible Challenger, I don’t think the asking price is that far out of line, 6 cylinder or not.
    The next owner could go two directions: stock restoration or all-out resto mod. They won’t lose either way they go.

    Like 1
  14. StephenS

    I owned a 71 Cuda Convertible slant 6. Red on white interior.
    Bought it used in 75 for about 1800 Canadian.
    Car had power steering, standard drum brakes, a manual spring loaded top, and and an auto tranny selector mounted on the steering wheel.
    No mechanical issues over 5 years but the rust was setting…
    got tired of it and traded it in on Saab 99.
    I still want to throw up every time I think of what I did.

    Like 0
  15. GOM

    I agree wholeheartedly. A few mod’s to the slant 6 would make this an excellent touring vehicle or weekend plaything. Even stock, they were no slouch. Not everyone wants a 6 MPG road rocket, and likely the lighter 6 would make this car faster in the esses than a 426 or 440. I’d have more fun corner-carving on secondary roads than I would doing burnouts and straight line street racing. To each his own, I guess, but I hope this relatively rare bird is restored as-is to six-in-a-row glory!

    Like 1
    • Robert Atkinson, Jr.

      True. Even the six-cylinder will propel this car to illegal speeds, so why the need to install capability you’ll only be able to use on the track or at the drag strip? The rarity of this combination is what makes is special and worth saving! The lighter front end improving the handling is a nice bonus! To be fair, others felt the same way, which is what drove John Z. DeLorean to develop the 230/250 OHC sixes for the Tempest and Firebird!

      Like 3
  16. Dan

    Restore this car back to original specs, including keeping the Slant 6 and bringing back the original hood. This is a bigger novelty than even a Hemi convertible and it may even win awards at Mopar shows from judges tired of seeing the same old “tribute” cars.

    Like 3
  17. Jay McCarthy

    It’s not difficult getting more horsepower out of the Leaning Tower of Power and you can beat like it’s rented and it just won’t break

    Like 1
  18. StephenS

    Owned a 71 Cuda Convert, red on white interior, slant 6.
    Purchased it in 75 and traded it in 4 years later for a Sabb99…worst mistake of my life.
    Car came with Power Steering, standard drum brakes, a spring loaded manual top, no console, just an auto 3 in the tree.
    Other than it beginning to rust up in various spots it ran trouble free for the 4 years I owned.
    Still can’t believe I let it go.

    Like 0
  19. V12MECH

    Salt belt rust bucket,6 cylinder, way too much ask, have a ’70 340 convert in shop now, same condition, customer got it for under $10k. They are out there.

    Like 2
  20. AnnasBigBananas

    Had a 70 red w/white Challenger cv with the tower of power & 3-on-the-tree. Bought it from the original owner in Bellflower CA, sometime back in the late 80s. When she told me at the time she bought the car it always got horrendous gas mileage. So, she complained and the dealer must’ve swapped out a Scat-Pak for an original 2bbl/single exhaust setup, because she went on to tell me that when she got homek she discovered parts in the trunk. Sweet ol’gal she was, she put the boxed up Scat-Pak up in the rafters of her garage and forgot about them.

    Like 0
    • St.Michael

      Scat-Pack or Hyper-Pack ? Hyper-Pack was a /6 performance package…

      Like 0
      • AnnasBigBananas

        How many have you had?

        Like 0
  21. Fish56

    Back in 1995-1996, I went to a local car show at Kohler Dodge in Naperville, IL. One of the cars for sale was a powder blue 1970 Dodge Challenger convertible, white top and interior, 225 slant 6. They were asking $14,500 if I recall correctly. Beautiful car.

    Like 0

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