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Exhaust manifold question.

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by BLAZEN70, May 11, 2003.

  1. BLAZEN70

    BLAZEN70 Registered Member

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    I need a cheap, quick fix. The RH manifold is cracked and im going to hit the junk yards soon to look for one. My question is: Do i need to look for the same cast # which is 3747042 or will one fit from another year, vehicle? It also dumps sraight down.
     
  2. Rusty68

    Rusty68 1/2 ton status

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    You dont need to match casting numbers as long as the point in the same direction as your center dumps. There are a bunch on ebay, just look under Ram horn manifolds. seems to me the last time I looked you can scratch up a pair for less then 50 bucks.
     
  3. Triaged

    Triaged 1/2 ton status

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    Why not use this as a good time to put some headers on it?
     
  4. BLAZEN70

    BLAZEN70 Registered Member

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    I would love to put headers on but im a little tight on funds right now. Since this is my daily driver i have go the cheap route for the time being.
     
  5. BLAZEN70

    BLAZEN70 Registered Member

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    I figured as much but, i just wanted to ask and make sure. No point wasting time on a wild goose chase. Thanks for the reply. /forums/images/graemlins/thumb.gif
     
  6. jasonkh2tg

    jasonkh2tg 1/2 ton status

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    Or If you wanted did not want to go to Headers you can always upgrade to corvette center dump ram horns with a 2.5" drop....same manifold style as olders 4x4 trucks but with a 2.5" drop vs a 2".... /forums/images/graemlins/wink.gif
     
  7. 71blaz

    71blaz Registered Member

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    I put a set 2.5" manifolds and 2.5" pipe on my blazer and they don't seem to have the same problems associated with headers. I think the truck shop sells them.
     
  8. Rusty68

    Rusty68 1/2 ton status

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    I to am running the 2 1/2 manifolds. After 2 different brands of headers melting things under the hood or wacking the frame I gave up. Not nearly the hassel of headers, and I didnt notice any power or mileage losses. Besides, they look really cool if you get them high temp coated.
     
  9. BLAZEN70

    BLAZEN70 Registered Member

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    I found a pair of (80's) Corvette manifolds on ebay for pretty cheap. Just a dumb question and i already think i know the answer, if i put those on do i need to replace all the pipe?
     
  10. BLAZEN70

    BLAZEN70 Registered Member

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    Rusty68, did you notice any increase in power, etc..? Just curious.
     
  11. jasonkh2tg

    jasonkh2tg 1/2 ton status

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    I have a set of ram horns with a 2.5" drop I was going to install them until..I got the bright Idea of installing Block huggers..(stupid mistake),,the engine cross member needed a bit of trimming to make them fit... /forums/images/graemlins/wink.gif
     
  12. SHINTON

    SHINTON 1/2 ton status

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    [ QUOTE ]
    I have a set of ram horns with a 2.5" drop I was going to install them until..I got the bright Idea of installing Block huggers..(stupid mistake),,the engine cross member needed a bit of trimming to make them fit... /forums/images/graemlins/wink.gif

    [/ QUOTE ]

    Wow...I am eyeballing block huggers right now at Summit Racing, can you send a picture of trimming needed?

    Anyone with pictures of headers installed? I tried to get new exhaust today but bolt in manifold broke off (to exhaust) and I am thinking of upgrading to headers rather than mess with the manifolds.

    Anyone have fit issues? I could care less about performance gains, am looking at Summit Block huggers, Summit Headers and Flowtech Headers. Thoughts, opinions?

    72 GMC Jimmy, 350, automatic, NP205....if that helps.

    Sam Hinton
     
  13. Burt4x4

    Burt4x4 3/4 ton status

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    I run Hedmens hedders. I actually just installed my second set. The first set I put in back in '94 and they were warped and leaking si this time I got Hedmen Elite series. Thick flanges and coated. I got them from Summit fer like 260 I think??
    The reason I like Hedmen is bacause the fit very nicely up tight near the frame rails out of harms way. Some full length hedders will hang way low, like Thorlys, sweet hedder but man they hang down low /forums/images/graemlins/frown.gif
    anyway good luck
    Burt
     
  14. Rusty68

    Rusty68 1/2 ton status

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    No, I cant say that I noticed any performance gain over the stockers with 2 1/4 pipes. It did however have a deeper tone and funny, but my cruising tempature went down almost 10 degrees. I agree headers have better flow and can make a few ponies, but for a rig that needs all the low end, you cant beat a set of rams for being durable and adaquate.
     
  15. jasonkh2tg

    jasonkh2tg 1/2 ton status

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    here is a pic of the how much crossmember needed to be trimmed to make block huggers fit...It's a pic of the drivers side that needed the most grinding...Im thinking of fabing my own crossmember so I can bolt it to the engine and have a solid engine mount... crossmember pic
     
  16. 6869704x4

    6869704x4 Registered Member

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    Ive got a set of Summit block huggers still in the box.
    The crossmember wasn't the only issue on mine. The starter interfered with them too. So I put them back in the box and bought some cheap headers from Advance. They fit great and were aroung $80 I think.
     
  17. Big Sean E

    Big Sean E Registered Member

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    I went with the flowtech ceramic coat headers, and couldn't be happier. They've kept their luster, and didn't have any serious clearance issues while bolting them up. One thing you may want to do is use shorty plugs. One of the plugs sits almost on one of the tubes, but the boot has shown no signs of damage, or trouble. Also, always use brand new copper gaskets (duh right?)/forums/images/graemlins/smirk.gif The cleaner sound and seat of the pants feeling is noticable.
     
  18. R72K5

    R72K5 Banned

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    if you find what the seller calls corvette manifolds, then you better find out the casting number and look them up to make sure, because only some of them in the early to mid 60s were the 2.5" exit ones and all others are 2" exits, ppl love to advertise ram horns as vette manifolds
     
  19. BLAZEN70

    BLAZEN70 Registered Member

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    That's some good advice. I've got my eye on a couple on e-bay. How hard is it to replace the studs if doesn't come with any? Where can i find bolts if i need to replace them? Anyone know?
     

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