Question on exhaust manifolds

Mopar Exhaust Systems

  1. Xp29h

    Xp29h FBBO Gold Member FBBO Gold Member

    Messages:
    4,226
    Likes Received:
    3960
    Joined:
    Aug 9, 2013
    Location:
    Maine
    Local Time:
    12:12 PM
    recently replaced a 383 hp engine with another. When I took the old 383 out, obviously pulled the exhaust manifolds off. Didn't give them much thought as the plan was headers for the new engine. Reason for the change was the 383 was not running well at all and couldn't get out of its own way..should also say 906 iron heads that had been redone and oversized valves and med cam.

    Fast forward to yesterday. Looked at the numbers off the old e. Manifolds. Looks like the drivers side is an actual hp but the passenger side numbers show its a regular manifold not an hp (magnum)

    That all said, here's the question(s) What if any performance issues would I have been experiencing with different manifolds? Would we have noticed any difference at all?

    Thanks!
     
  2. miller

    miller Well-Known Member

    Messages:
    4,083
    Likes Received:
    2005
    Joined:
    Jan 5, 2014
    Location:
    Tom Bean,Texas
    Local Time:
    11:12 AM
    Flow. Non HP manifolds won't flow as good. Don't know if that'll answer your ?.
     
    • Thanks! Thanks! x 1
    • PurpleBeeper

      PurpleBeeper Well-Known Member

      Messages:
      4,526
      Likes Received:
      3279
      Joined:
      Mar 20, 2011
      Location:
      Chicago
      Local Time:
      11:12 AM
      I doubt if you would have noticed a difference
       
      • Thanks! Thanks! x 1
      • e-440

        e-440 Well-Known Member

        Messages:
        91
        Likes Received:
        87
        Joined:
        Mar 1, 2015
        Location:
        usa
        Local Time:
        11:12 AM
        There are differences and that is that all HP manifolds have a 2 1/2 outlet and non HP manifolds are 2 inch outlet. Non hp manifolds are great for a bone stock engine, but that is about all they are good for. Find the right side manifold and be done with it.
         
        • Thanks! Thanks! x 1
        • Xp29h

          Xp29h FBBO Gold Member FBBO Gold Member

          Messages:
          4,226
          Likes Received:
          3960
          Joined:
          Aug 9, 2013
          Location:
          Maine
          Local Time:
          12:12 PM
          Thanks for replies! I don't plan on using them at all. The motor that's in the charger has headers. Once I figure out what I really need to rebuild the 383, I'm sure I'll put headers on that as well.

          I knew the sizes were different. I couldn't imagine that it would flow as well but wasn't sure how bad it would have been or even noticeable. With all the other issues with the motor, it certainly couldn't have helped.

          Again thanks!
           
        • BeeBoy2Bee

          BeeBoy2Bee Member

          Messages:
          18
          Likes Received:
          12
          Joined:
          Sep 4, 2016
          Location:
          Cloce to DC.
          Local Time:
          12:12 PM
          Interesting subject! I'm interested in an original '70 Charger with the 383/335HP and 727 trans. Have not been able to view the car yet. Would that engine/trans application have the HP manifolds with the larger outlets?
          :thankyou:
           
        • e-440

          e-440 Well-Known Member

          Messages:
          91
          Likes Received:
          87
          Joined:
          Mar 1, 2015
          Location:
          usa
          Local Time:
          11:12 AM
          it should have if they are still there.
           
        • BeeBoy2Bee

          BeeBoy2Bee Member

          Messages:
          18
          Likes Received:
          12
          Joined:
          Sep 4, 2016
          Location:
          Cloce to DC.
          Local Time:
          12:12 PM
          Thanks e-440, the car is undisturbed/original except for new performance system with a X pipe midway from the manifolds back.
           
        1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
          By continuing to use this site, you are consenting to our use of cookies.