High performance manifold differences

Discussion in 'Mopar Exhaust Systems' started by 70scatpack, Jul 10, 2018.

  1. 70scatpack

    70scatpack FABO Gold Member FABO Gold Member

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    What’s the difference between the 1970 high performance 340 and 1973 high performance 340 manifolds besides the casting numbers?
     
  2. inertia

    inertia Well-Known Member

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    The early ones have a flat pipe flange using a gskt. The later ones have a bell/ball flange, no gskt reqd.
     
  3. 70scatpack

    70scatpack FABO Gold Member FABO Gold Member

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    Thanks,port and flange end diameters are the correct?
     
  4. rumblefish360

    rumblefish360 so close yet so far away

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    Good question
     
  5. pishta

    pishta I know I'm right....

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    Good catch, I didnt know that.
     
  6. Tom Swope

    Tom Swope Well-Known Member

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    Partially correct. Early manifolds had gaskets on both sides as stated. Later performance manifolds from 1971-74 used a gasket on the left side as the early manifolds and a ball joint connection/floating flange connection on the right side requiring no gasket. The right manifold (626 casting) was also used on 1971-74 b and e body applications with 340/360 engines.
     
  7. ir3333

    ir3333 Well-Known Member

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    they are shaped completely different although the drivers' side are similar.
     
  8. toolmanmike

    toolmanmike FABO Staff Staff Member FABO Gold Member

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    Isn't there a difference in outlet size as well? I need to look it up here in a bit.