340 MANIFOLD VS MAGNUM MANIFOLD ?

Magnum Engine Swaps

  1. CRAMAR

    CRAMAR Well-Known Member

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    I am thinking about putting a 5.9 magnum where my 318 is.It's in a duster.Will the exhaust pipe fit the magnum manifolds or will i have to get new exhaust?
     
  2. mod5v

    mod5v Well-Known Member

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    You will not be able to use the Mag manifold on driver side. It sets to low and will hit the steering box. you can use the passenger side. outlet position is changed so most likely you will have to change the head pipe.
     
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    • Treblig

      Treblig Well-Known Member

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      The 96/97/98 jeep grand Cherokee V8 passenger side manifold will fit real nice and give you flow that is close to the 340 HP manifolds. On the driver's side use the 70s 340 driver, it will fit with P/S or anything else you might have on your engine.
       
    • toolmanmike

      toolmanmike FABO Staff Staff Member FABO Gold Member

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      And TTI makes pipes to fit different manifold numbers. They may not work with your exhaust depending on what it is but could probably be modified.
       
    • YY1

      YY1 Well-Known Member

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      340 manifolds would be a great ting for someone to repro-

      they'd have a lot more customers than just people with 340's
       
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      • toolmanmike

        toolmanmike FABO Staff Staff Member FABO Gold Member

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        • Thanks! Thanks! x 1
        • YY1

          YY1 Well-Known Member

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          How much are they?
           
        • tonysrt

          tonysrt FABO Gold Member FABO Gold Member

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          I bought my repro 340 exhaust manifolds from Shaker and they were $600.
           
        • Treblig

          Treblig Well-Known Member

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          360 magnum Jeep grand Cherokee passenger manifold - $60
          340 HP 70s driver's manifold $150 -$100
           
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          • plumcrazy 101

            plumcrazy 101 Well-Known Member

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            Just working now on putting a set of 68 to 70 340 manifolds on the EQ Magnum heads. There is a mismatch on the ports that have to be corrected. Not only are the center ports wider but the lower portion port on the exhaust will not seal on the exhaust flange on the heads. Time to make up some flange adapters or do some welding on the exhaust manifold.
             
          • tonysrt

            tonysrt FABO Gold Member FABO Gold Member

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            I was looking to do the same thing with the 360 EQ heads and the repro exhaust manifolds. Has anyone else experienced this problem and would the edelbrock heads be the better way to go eliminating this port mismatch? Maybe the Indy MA-X heads, but looking at their picture might be the same problem.
             
          • rumblefish360

            rumblefish360 So close, yet so far away FABO Gold Member

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          • toolmanmike

            toolmanmike FABO Staff Staff Member FABO Gold Member

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            Yes but available. I gave seen nice used ones go for just a bit less.
             
          • plumcrazy 101

            plumcrazy 101 Well-Known Member

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            The Edelbrock LA heads will not accept the 68 to 70 Hi Po exhaust manifolds but I have not tried their Magnum head with the manifolds.
             
          • plumcrazy 101

            plumcrazy 101 Well-Known Member

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            Shaker Hood still has these manifolds for $600.00
            I believe that Tom from Rocket Industries is looking after the business after Ben Snobar passed away.
             
          • rumblefish360

            rumblefish360 So close, yet so far away FABO Gold Member

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          • Treblig

            Treblig Well-Known Member

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            I've never tried to install 340/magnum manifolds on EQ heads but an adapter should work if it doesn't push the manifold too far out away from the engine causing interference????
             
          • plumcrazy 101

            plumcrazy 101 Well-Known Member

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            Just making the plates up today out of 3/32 thick 2 1/2" flat bar.
            Going to try steel on cast iron with high temp silicone as the sealer.
             
          • Treblig

            Treblig Well-Known Member

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            Steel on cast shouldn't be a problem....drag racers have been doing it for decades. I would use the EQ gaskets and the 340/magnum gasket on the respective surfaces....but that's just me. Silicone will give you a little more clearance, but you may not need the extra clearance???????
             
          • leblanc

            leblanc member 2883

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            If you boost power a bit 2.5'' exhaust might not be a bad idea too.
             
          • plumcrazy 101

            plumcrazy 101 Well-Known Member

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            That was the plan to use the 340 heat shield gasket but have not made my mind up on the other side.
             
          • plumcrazy 101

            plumcrazy 101 Well-Known Member

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            Complete 2 1/2" exhaust going in with a cross over pipe
             
          • leblanc

            leblanc member 2883

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            :thumbsup:
             
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