Magnum Exhaust Manifolds in an A Body

Mopar Exhaust Systems

  1. dustoff440

    dustoff440 Well-Known Member

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    Stay tuned, the magnum exhaust manifolds from a Durango are enroute from HemiEd and I will be heavily documenting their mods and installation on my 70 Dart(orig. /6 with TransDapt /6 to 360 motor mounts). Im hoping there are a lot of guys who will be helped by this. Im sure that I'm not the only one who is interested in inexpensive high flow factory exhaust manifolds that are readily available either new or used that fit with minimum modifications for a fraction of the price of 340 manifolds. I saw an article that 340 manifolds flow only well enough to make 11 more horse power on the dyno than standard v8 manifolds(a body manifolds). Magnum manifolds were designed to have high flow rates. In fact if I'm correct, 92-93 Magnum manifolds have a 2 1/2 outlet and following years have a 2 1/4 outlet.. I MIGHT not be all that far off by saying that magnum manifolds flow almost as well as 340 manifolds
     
  2. mtandrews

    mtandrews beware the Ides of March FABO Gold Member

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    cool! I for one will be watching...
     
  3. Tnplumber

    Tnplumber Well-Known Member

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    Me Too.
     
  4. BLOW-DART

    BLOW-DART Well-Known Member

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    I'M sure they will fit pretty well in your 70. i just pulled a set off a 318 in my 64 barracuda that fit with just some milling on the driver's side. only "bad" part was they were so close to the steering shaft sleeve at the firewall they melted out the seal for the column, not a big deal though.

    good luck!
     
  5. fzmax

    fzmax Well-Known Member

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    Magnum manifolds make the same power as 340 manifolds. There are probably a bunch of other threads on here about it, but here is a write up with dyno tests.
     
  6. 73NorthernDuste

    73NorthernDuste Well-Known Member

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    Have you had a chance to try the manifolds? I've got a set on the 360 I am going to put in my duster. The guy I bought the engine off had them in a 67 charger and did a little grinding on the drivers side but still wondering about an a-body

    thanks
     
  7. tubbedamx

    tubbedamx Location Boise, Idaho

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    If you were to use these manifolds on your a-body, what would be the plan on exhaust pipe?

    Is there anybody who could make mandrell bends to existing tti exhaust system?

    You have my interest.
     
  8. 65Val

    65Val Average Length Member

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    Subscribed...
     
  9. BlueSwinger

    BlueSwinger Professional Lurker

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    Subscribed here also. I already have a set of the '92-'93 ones that I'm using on my Dart do-or-die.
     
  10. mtandrews

    mtandrews beware the Ides of March FABO Gold Member

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    hey wait a minute! Subscribed? how do i do that?!?
     
  11. dustoff440

    dustoff440 Well-Known Member

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    I did some measuring and it appears that there will be substantial grinding on the underside of the manifold to clear the p/s box. I might even have to cut out a piece and weld it short of the original dimensions. I know this seems like a lot of frigging but most decent 340 manifold sets I have see recently are between 250-400 bucks!!! I am considering a drivers side only 340 manifold and the dakota on the passenger side.
     
  12. BlueSwinger

    BlueSwinger Professional Lurker

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    Really? I wonder what's up with that. I swear there were some threads around here where it showed just a tiny amount of grinding to clear the PS box, then they fit fine. I know every individual car can be different though.
     
  13. streetdak

    streetdak Well-Known Member

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    all the threads on here are shown on no p/s cars. Magnum manifolds come into massive direct contact with power steering box and p/s column. Im not aware of any way to effectively weld the cast iron manifolds, takes an incredibly talented welder to weld cast iron. Not going to work if you have a power steering car. Just speaking from expierence
     
  14. BlueSwinger

    BlueSwinger Professional Lurker

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    Yeah, I see that now, I was remembering wrong. Well, unless DustOff440 figures out a reasonable way to do this, looks like I'm converting to manual steering then. What's a little more $$$ at this point LOL
     
  15. caferacerx

    caferacerx BAND MEMBER

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    they also interfere with the Z-bar on manual trans cars, one more reason I am thinking of going with a hydraulic clutch
     
  16. streetdak

    streetdak Well-Known Member

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    Right??? I was tempted to swap my 74's manual stuff to my 73's and vise versa so I could drive the damn thing again lol, but we have allready cut and re-drilled and re-bent my idler arm mount for header clearence. looks like im commited! lol
     
  17. BlueSwinger

    BlueSwinger Professional Lurker

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    Oh, I should get a clarification. You said p/s column as well. You mean swapping out the whole column is necessary to make those manifolds fit too? Or just changing to manual steering with the p/s-column-to-manual-box adapter will clear? If I need to swap out the whole column, then I may just abort mission and go to headers after all, since the conversion costs would add up way fast.

    Sorry to hijack the thread, but it's obviously relevant info!

    (and, thanks!)
     
  18. streetdak

    streetdak Well-Known Member

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    As far as stock, esp with stock column shifter, the power steering column will directly interfere with the manifold. Someone on here was talking about being able to modify a stock p/s column, but i honestly do not know of any way to do that. So if you can find a way to modify it and cut the collar down, then maybe so, the biggest interference is definitely the gearbox and column auto linkage.
     
  19. needsaresto

    needsaresto Well-Known Member

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    There is a tool bar at the top of the post. One box is labelled thread tools. You will find a subscribe option there.

    Also,there is an option in your usercp page to automatically subscribe to a thread whenever you make a post to it.
     
  20. BlueSwinger

    BlueSwinger Professional Lurker

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    Thank you for all your info. I will still probably convert to a manual steering box because I want to anyway, then when the time comes, I will probably just bite the bullet and use headers and save these manifolds for a car they're better suited for. Not worth all the trouble! Thanks again.
     
  21. MopaR&D

    MopaR&D Nerd Member

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    Crap, I was really hoping I could save some money using these manifolds in my '70 Duster but there's no way I'm converting to manual steering. I spent big bucks for the awesome Firm Feel Stage 2 PS box and I'm not about to yank it out... So what other options are there for exhaust manifolds? How do the later 340 manifolds compare to the earlier ones? I found a pair of 1973 340 ones starting at $100 on eBay, decent deal or no?
     
  22. dustoff440

    dustoff440 Well-Known Member

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    Ok guys have to eat big crow on this one. Trying to get the Dakota manifold on the drivers side to fit is going to mean major major frigging. If I knew some one around here that was good at welding cast iron I would drive on with trying to install it as cutting out a portion and welding it short of the original dimensions would work. Just milling the mounting surface helps with the column interference but didnt help one bit with the p/s box issue. For guys with standard boxes I'm guessing that the milling 1/4 inch off the mounting surfaces will help tremendously with the columnn situation. I think that grinding the p/s box some and grinding the hell out of the manifold would work but the manifold at that point would be very thin. So....Im going with a half install...I got an early 340 A body manifold from another FABO member that Im going to install on the drivers side and the Dak big outlet manifold on the passenger side. I'm tired of frigging around and ready to start cruising!!!!
     
  23. BlueSwinger

    BlueSwinger Professional Lurker

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    That's an option for me too I suppose, but I'm actually thinking of just biting the bullet and going for some TTI's. Less trouble after all.

    I wish to heck I was exaggerating, but by the time I'm done with the one car, I'm going to have another whole car in extra parts! Not a bad position to be in I guess, looking at the bright side LOL
     
  24. dustoff440

    dustoff440 Well-Known Member

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    Yea, I'm in the same position as you BlueSwinger, I have collected tons of extra parts and not sure whether to build a race 70 Dart or keep all the spare stuff in case some idiot crashes into my car and I won't have to go on the hunt for parts. The only problem is that a while after I have finished a car Im wanting to get a different one and build that up.
    Ive had half a dozen cars I built and just about the time I run out of stuff to do to it, I want a different car, could have something to do with ADHD.
     
  25. BlueSwinger

    BlueSwinger Professional Lurker

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    I'm not too worried about it... one of the nice things about these old Mopars is that so many parts are interchangeable with so many others. I have a second complete drivetrain, 2nd disc setup, 2 sets of wheels (none of which fit on my car now that I've gone to the big discs and drums LOL), now these manifolds and on and on... a 2nd A-Body later will be SO much cheaper than this with the big head start if I plan it right! And these parts aren't going to get easier to find.

    About the Doug's or even TTI's... they seem cheap now since I won't have to convert over so many other things to make these fit... everything to convert the column, floor shift, steering all add up to a lot more work and money! Not to mention the interior work to make it right.
     
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