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Projects *Help* Identify this 283 Exhaust Manifold

Discussion in 'The Hokey Ass Message Board' started by KustomRocket88, Jan 4, 2014.

  1. KustomRocket88
    Joined: Dec 12, 2009
    Posts: 291

    KustomRocket88
    Member

    Hello,

    [​IMG]

    I've been doing research, I've checked numbers, I've checked Ebay. I'd like to put an end to this mystery once and for all. Please be blunt and tell me if I'm wrong, I believe I have an original '58-'63 Corvette exhaust manifold (on bottom in above photo), with just a generic stock 283 manifold (on top in above photo).

    Am I correct, or is just a stock set of exhaust manifolds? The numbers I got on the supposed Corvette manifold read 3749865, LH 8.


    The output on this one seems to have thinner casting than the other, I have pictures below:

    [​IMG]

    [​IMG]

    I want to run these and put on a dual exhaust system on my 63 Chevy. I'm assuming factory headpipes I order, one of them won't just bolt up directly to this, would I have to get a reducer or have a pipe flared?

    These might be dumb questions but not to someone who is trying to learn and never really done engine work, or put one together. Any kind help is appreciated here. Thank you :)
     
  2. dave lewis
    Joined: Dec 12, 2006
    Posts: 1,378

    dave lewis
    Member
    from Nampa ID

    Not corvette..
    The one that appears smaller really is not..
    Both are 2" outlet..the flat face is for the heat riser..uses a flat gasket. The other side withe the beveled recess uses a donut....
    If they were corvette units...they would measure 2.5"...

    Posted using the Full Custom H.A.M.B. App!
     
  3. KustomRocket88
    Joined: Dec 12, 2009
    Posts: 291

    KustomRocket88
    Member

    Thank you Dave. Only, the bottom one (with the triangular flange at the left end) measures more than 2" though, This is where I got confused. I'd assume and think that'd be awesome if they're both 2" to bolt up my normal exhaust!
     

  4. KustomRocket88
    Joined: Dec 12, 2009
    Posts: 291

    KustomRocket88
    Member

    Thank you CTFuzz but I checked there, says Corvette and Passenger car. My question is do all LH manifolds have that bracket?
     
  5. dave lewis
    Joined: Dec 12, 2006
    Posts: 1,378

    dave lewis
    Member
    from Nampa ID

    Yes..left hand manifolds have the gen/alt boss..
    If you doubt the size info I posted. ....measure the bolt circle of the studs...both should be the same..
    The 2.5" vette manifolds have a bigger spacing...it just happens to be the same as a 3" header collector gasket. .

    The passenger / lower performance manifolds use the 2.5 " header collector gasket..

    So yeah...compare the manifolds you have. .if they have the same bolt spacing...you have a matched pair !

    Dave

    Posted using the Full Custom H.A.M.B. App!
     
  6. KustomRocket88
    Joined: Dec 12, 2009
    Posts: 291

    KustomRocket88
    Member

    Thank you Dave! Yes, I do actually have a matched pair. My apologies, it turns out I was just measuring the beveled point and both are 2". I appreciate the help here! Also, the heat riser slides onto both sets of studs.
     
  7. Corvette manifolds came in 2" & 2 1/2" outlets both.
     
  8. It is possible they're Vette manifolds. Only high HP Vettes had the 2 1/2" ram horns.
     
  9. This;)
     
  10. KustomRocket88
    Joined: Dec 12, 2009
    Posts: 291

    KustomRocket88
    Member

    In that case....killer! My numbers match those of Corvette manifolds...definitley hanging onto these. Now I got an excuse to spend an extra buck and get the finned valve covers :D
     
  11. KustomRocket88
    Joined: Dec 12, 2009
    Posts: 291

    KustomRocket88
    Member

    Thanks for all your help guys, I appreciate it
     
  12. Model A Vette
    Joined: Mar 8, 2002
    Posts: 1,075

    Model A Vette
    Member

    I come up with 3749965 not 9865. It is easy to mistake an 9 for an 8.
    They were used on passenger cars and lo-po Corvettes on the drivers side from 1958 thru 1964. Described as straight dump, front bracket with side holes, 2".
    They were a pretty common manifold not a rare Corvette only manifold.
     

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