Adding V8 Power


I found a 1971 Dodge Dart Swinger with a Slant-6 engine. Can the Slant-6 be removed and replaced with a 340 or other V8 without a lot of modification?


Yes, The 340 c.i. small block MoPar is a great way to add more than enough power to your Swinger.
You will need:
  • Conversion Motor mount brackets
  • Bigger radiator
  • Rear axle
  • Front Torsion Bars
  • Transmission
  • Driveshaft
  • Brakes, etc…
As you can see the list gets long quickly… and you’ll need to do some hunting to find all of the parts, but it can be done… Those who have done this often rely on purchasing a parts car or are ready for the hunt at local swap meets, junk yards, or online auction sites. Best of luck with your great project! Wrench Safe, Mark
Reply to panamfam
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37 Responses to “Adding V8 Power”

  1. blog entry

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  2. การดูแลสุขภาพ

    You actually make it seem so easy with your presentation but I find this topic to be
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  3. Brian

    I hve a Duster with a Slant6, wasn’t worth the head ace of switching motors, alot of parts 2 track dwn & manual labor 2 do n the swamp, I left the 6 cyl in & enjoy driveing the kar…..

  4. David James

    Or you could find some Clifford Performance headers and their 4 barrel manifold and eliminate all the change-overrs.

  5. Edward Greenberg

    The Chrysler 225 Slant Six is arguably the best engine to ever come out of “Detroit”. It is indestrutible. We put 253k on a 1965 Dodge Dart, sold it and last we heard the buyer was close to 350k. I would forget the added power and keep the engine “you can’t kill”, gives much better fuel economy and is more reliable than any engine you are thinking of putting in it. If you use the car for racing….I understand. No other good reason to remove a slant six unless the engine is shot. I have never seen or heard of a “worn out” Slant Six.

  6. Reg van Buuren

    Good hunting !!! & join a Doge Dart club … should be able to get bits off fellow members – swapping …

  7. Tom Schultz

    Or, you can give your dart to me!!! Sounds like a great project! Definitely upgrade your brakes and suspension as others have already advised.

  8. D

    I have a slant 6 that makes a sound like a child’s bicycle bell ringing. It appears to be in the valve train. It can do it while idling or in gear. It does this inconsistently (not all the time). ANy ideas?

    • Customer Service


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  9. Bruce

    Would it be a more fun build out to turbo/supercharge the slant six? A rear axle upgrade/transmission & radiator might be all that is needed to make a good sleeper. Slant sixes are known for durability.

  10. Michael

    I found a 1966 Dodge Dart GT and am having the Slant 6 replaced with a 318 V8. IMHO, its the set-up Dodge SHOULD have made to compete with the Mustang and Camaro.

  11. Dave

    It used to be that you had to change out the S6 K-member for an LA engine K-member. It appears now that conversion engine mounts are available to readily turn this swap into a bolt in! In fact, conversion mounts are now available to swap in any Mopar V-8 including B engines and modern HEMIs.

  12. Robert Raduechel

    You get the K-member out of a v8 dart. It has disc brakes 5 on4.5 wheel bolt pattern. Heavier torsion bars. Get the 8.74 complete rear end with 5 on 4.5 wheel bolt pattern. A 727 small block trans. Should be able to find the driveshaft at a wrecking yard. Get the master cylinder,power booster and combo valve also. You may also be able to get a factory OEM floor shift unit. Makes a great vehicle. ps don’t forget radiator up grade and fan shroud.

  13. Gio

    Ide heard you can port ylure slant six someway and increase the hp,does anyone know anything about this?

    • Customer Service

      Hello Gio,

      Porting is simply the process of smoothing out the intake and exhaust ports to allow better flow.

      Standard abrasives makes a gear kit to get the job done.
      Here’s a link to one source to purchase it:


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  14. Scott

    What rear axle can replace a 1954 Chevy pickup torque tube. And what else do I need to replace the rear axle?

    • Customer Service

      Hello Scott,

      Your stock rear axle is 62″ wide (wheel mounting surface to wheel mounting surface)
      1955 to 1959 Chevrolet 3100’s have the same width and open driveshaft.
      other rear axles with close widths include: 1968-72 Chevelle, 1970-81 Camaro.
      There are of course others worthy of checking out, but you’ll likely need to weld in new spring perches on whatever you decide to use.

      You’ll need a new open driveshaft, and most driveshaft companies can build one to the exact specs you need.

      And you’ll need a transmission. There are many options here, but most chose a T5 manual or 700r4 automatic.
      you may need an adapter plate to make the transmission conversion.

      Hope this helps,

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      We’d love to have you be a part of our community. We are convinced you will enjoy the benefits of becoming a member and having access to the best instructional how to videos and professional tips. We would like to offer you a special promotion for your first-year membership.

  15. Tj donahoe

    Leave the slant six in there….you can up the power on it it …you would be amazed…do some research….mopar or no car…

  16. Schmidty

    I’m looking for a 1955 Chevy Steering upgrade. I’m thinking something out of an early 80’s GM model.
    I’d like to take the entire system including wheel/column, shaft, gearbox, hoses, compressor, etc.
    Any suggestions welcome.

  17. Dave olsen

    To go along with this, I have a. Friend with a 59 Edsel Ranger and he has a 6 cyl stick in it and would like something like a 390. Can this be done?

    • K9KNS

      V8 into a Ford 6 cylinder car should be a piece of cake. I put a 427 into a 6 cylinder 1963 Galaxie. Radiator needed upgrade and we used a bigger trans.

  18. panamfam

    Years back, I put a V8 & transmission in a slant-6 74 Duster. I swapped out the whole K-Frame from a V8 car. no alignment issues. I should have changed all the stuff, but didnt. never had any issues.

  19. wayne

    back in the late 70’s i had a Dodge dart with slant 6. i built a 273 hipo and installed it the only thing i had to fabricate a motor mount for the passenger side.i used same transmission and rear in. from 0 to 30 mph it moved like a lead sled but it would fly. low to second @ 45mph,second to drive @ 95mph and still got 21 mpg. car ran for a long time until i got married,lol

  20. William Valtierra

    Would I have to change everything in a 6 cylinder Mustang to put a mild 289 in it? Transmission, rear end spindles etc…

    • Customer Service

      Hi William. Yes, to do the job correctly and not have a weak link in system, the front spindles, springs, steering linkage, rear axle, transmission, brakes, radiator, etc… would all need to be upgraded.

  21. Bob

    IF you have to ask this question then don”t try it about the most simple swap in the world //all the rest of things named should be done for safety but that was not the question !

  22. Ron langevin.

    440 is fine….I have one in my superbird, but…the cost of a steel crank 440, block, 904 heads, closed or small chamber version, boring, new pistons can cost a bunch. To redo my S bird, motor home block, 6pac, etc was more than a crate 426 Hemi. And after that, the rest of the parts. There is no such thing a junk yard parts anymore and anyone who says there is full of it. There is a couple of exceptions however if tiu live in certin areas like Eastern Nebraska, Mossuri, or the Carolinas. Other than that, good luck. The way to go might be to rebuild your slant six. You can add a Austrailian version of the Hyper-pac, headers, bore .060 and bring it up to 9.5 compression. Add a torque cam, a roller timing chain, and perhaps a 2 core radiator. You willbe up to around 175 HP by that time and under $4,000. If you want to go to 250, get a turbo setup. One final thing is brakes. You will need to add disk fronts. Use the dart, demon, duster setup and the 11 inch disks. You can get a
    Current version of this set-up from THE RAM MAN, INC. HE KNOWS ALL THERE IS TO KNOW ABOUT MOPAR BRAKES. You will be far more satisfied with doing it this way than the 440 Way unless it would be for straight line running. Save my address and I am available to give you advice any time. I am a Mopar restorer, a former MOPAR late model and sprint car driver, etc.

    • Non believer

      Where exactly can you just “get a turbo setup” for a slant 6? Header? Just a custom header alone would probably equal the cost of the turbo. Considering there is no “turbo setup”, you have to piece it together. Good luck with that. In the end, it would probably equal the cost of a V8 swap, or pass it and still not have as much power nor be as reliable.

      He’d be better off, instead of looking for “junkyard parts”, to use aftermarket replacements. Brakes, suspension, radiator, etc…

      So…. Where is this slant 6 turbo setup again? IMO, he’d be better off swapping the V8.

      • Denis

        Clifford Racing Has slant 6 headers, dual carb manifolds & carbs and camshafts. Enough to more than double stock power without a turbo. 6=8.

        • Michael

          You guys from Europe or Japan? Proper American Muscle MUST HAVE a v-8. If you insist of 6-cyl muscle, drop in a Nissan GTR or BMW M-3 engine, even though its pure sacrilege!!

  23. Virginia Harlow

    I had this conversion done back in 1980 in Mechanicsville, Iowa! Back then it only cost me $700. Good luck, it turns into a lightweight Road Runner hot rod! Well worth it!