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headers for a '90 K5

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by mtnman4x4, Feb 12, 2003.

  1. mtnman4x4

    mtnman4x4 Registered Member

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    headers for a \'90 K5

    Anybody have luck putting headers on a '90 K5 with a sm465 mated to a np241? I've tried 7 different brands and haven't found clearance for the passenger side.
    Thanks,
    Paul /forums/images/graemlins/usaflag.gif/forums/images/graemlins/k5.gif /forums/images/graemlins/usaflag.gif
     
  2. sled_dog

    sled_dog 1 ton status

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    Re: headers for a \'90 K5

    how do you mean clearance for the passenger side? you mean clearing the driveshaft?
     
  3. mtnman4x4

    mtnman4x4 Registered Member

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    Re: headers for a \'90 K5

    Have had trouble with the frame rail and/or the bell housing. The closest I got was a 1/4" clearance, which when torqued would ram the headers into the frame. /forums/images/graemlins/ears.gif
     
  4. Derf00

    Derf00 1/2 ton status

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    Re: headers for a \'90 K5

    What have you tried? /forums/images/graemlins/confused.gif
     
  5. sled_dog

    sled_dog 1 ton status

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    Re: headers for a \'90 K5

    Thats wierd never heard of anyone having such problems with headers. what headers have you tried?
     
  6. mtnman4x4

    mtnman4x4 Registered Member

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    Re: headers for a \'90 K5

    I've tried edelbrock, hedman, gibson, flowmaster,blackjack,shortys blockhuggers and a few others.
    The problem seems to be in the way the 465 bellhousing mounts. It favors the passenger side for some reason. Might be the output shaft alighnment for the np241.
    I've thought about custom but can think of a lot of other things to do with $600 /forums/images/graemlins/thumb.gif /forums/images/graemlins/k5.gif /forums/images/graemlins/usaflag.gif.
     
  7. jc71355

    jc71355 1/2 ton status

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    Re: headers for a \'90 K5

    I have an auto but I'm running dynomax headers with no clearance issues. They are a little too close for my taste to the shackle but it still works.
     
  8. OL14BLAZ

    OL14BLAZ 1/2 ton status

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    Re: headers for a \'90 K5

    Have you tried Doug Thorley Headers on there application page they have specific headers for all years of Blazers 2 & 4WD models. You might email them or give them a call and tell them your prolbem and they might be able to help you out. /forums/images/graemlins/thumb.gif

    Just my .02 worth.

    Eric /forums/images/graemlins/usaflag.gif /forums/images/graemlins/k5.gif
     
  9. dyeager535

    dyeager535 1 ton status Premium Member

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    Re: headers for a \'90 K5

    Well, if the only issue is the 465 bellhousing, anyone running that tranny with headers would have that problem, and I don't think thats the case. The furthest out the bellhousing sits is where the starter is, (the 168 tooth bellhousings have a bulge for the starter that sits further out than the vertical bolt pattern of the bellhousing to block) but since the starter is already there, and almost the same distance "out" as the bellhousing bulge, I can't see the headers being angled towards the center of the truck.

    I had always figured the "no manual transmission" note for the '87-91 trucks had to do with the slave cylinder/hose. (But'85-91 is really the same in that case anyways)

    I'm getting ready to buy some headers myself, while looking last weekend at the swap meet, I noticed some differences in the length the headers stick "out" from the block. Some looked like they would be too close to the frame, but easy plug access, while others were close to the block for lots of clearance, but difficult plug access.

    The headers you tried, are they all 4wd manual transmission headers?

    One other thing, have you thought about going with poly trans/engine mounts to limit the torque of the engine more? 1/4" seems awfully close though, even if you do limit the engine movement more.
     
  10. mtnman4x4

    mtnman4x4 Registered Member

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    Re: headers for a \'90 K5

    Some were for the 4wd/4-speed, some others were universals. I have replaced the engine/tranny mounts with poly.
    None of it makes any sense to me either. The headers that came closest are the z71 headers, i would just have to drop a pipe to run around the external clutch slave.
    Hopefully I can find someone the same setup who has figured this out.
    /forums/images/graemlins/usaflag.gif /forums/images/graemlins/k5.gif /forums/images/graemlins/usaflag.gif
     

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