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? for anyone with big block and headers

Discussion in 'The Garage' started by Yukon Jack, Mar 22, 2003.

  1. Yukon Jack

    Yukon Jack 1/2 ton status

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    /forums/images/graemlins/1zhelp.gif I am swapping a 454 into my 1969 K20. I have it sitting in the frame now and have a problem with the passenger side header. I bought Dynomax Cremacoated headers for a 67-72 big block 2wd truck (no bb trucks until 1973). The collector on the passenger side is staring right at the transfer case and I don't think there is going to be enough room to make a bend to go up over the transfer case.
    Some have recommended I use the 73-87 big block 4x4 headers.

    It would help me a lot if I could get some rough measurements of how far your collector hangs down (nothing precise). A measurement from the bottom of the flange at the engine to the top of you collector so I know how far they hang down would be great along with I.D. of your header manufacturer and what application they are for.
    Would also be helpful to get a rough measurement from the back of the flange at the engine to the end of the collector so I know about how far back the collector is from the engine.

    If anyone who has done a big block swap in a 67-72 can tell me what headers they used, that would be helpful too.

    Thanks
     
  2. thatK30guy

    thatK30guy 1 ton status Premium Member

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    I read in a magazine that in order for the '67-'72 K-series trucks to run a BBC and headers, you will need to get an engine crossmember from any '73-'87 truck, or up to '91 on Blazer or Sub, and remove the stock member in your '69. By using the newer member, it will allow the proper clearance to run some newer headers that fit the '73-'91 years. /forums/images/graemlins/wink.gif
     
  3. rodzzilla

    rodzzilla 1/2 ton status

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    A friend of mine used 68-72 Chevelle headers on his Jimmy. I will check w/him to see what problems he ran into. I know the collector doesn't drop below the frame.
     
  4. RingMaster4x4

    RingMaster4x4 1/2 ton status Premium Member

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    My headers are off a 1978 Nova.
     
  5. Yukon Jack

    Yukon Jack 1/2 ton status

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    I looked around the local junkyards in town and couldn't come up with that crossmember setup a while ago. A guy even e-mailed me the article I think you are referring to. I have it scanned if anyone wants to read it.

    Keep the suggestions coming, its appreciated!
     
  6. Sandman

    Sandman 3/4 ton status Author

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    [ QUOTE ]
    A friend of mine used 68-72 Chevelle headers on his Jimmy. I will check w/him to see what problems he ran into. I know the collector doesn't drop below the frame.

    [/ QUOTE ]

    This is what I did. I had to cut out part of the frame on the passenger side and grind off part of the motor mount on the drivers side. Much higher and tighter fit than the old Dynomax ones that I had.
     
  7. Yukon Jack

    Yukon Jack 1/2 ton status

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    Am I correct in assuming you all are runnng your passenger exhaust pipe on top of your transfer case? That is how my stock exhuast was prior to pulling the SB engine.

    My truck has a Rockwell but it should sit very similar to those who are running the NP205.
     
  8. willy s wagon

    willy s wagon Registered Member

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    I have a 72 k-5 w/454,I run a set of Hedman headers I ordered from Summit.I don't recall the part #. They are for 67-81 4wd applications and they do fit with slight clearance problems. The #1 primary hit the motor mount until it self clearanced!The distance from the back bolt on #8 cyl. to approx. centerline of collector flange is 21".The collectors are cut to 2" then 2 1/2" exhaust bent up to clear t/case on passenger side, drivers side is the same to keep both lengths equal. They have been on 10 years now and no probs. so far.(other than multiple gaskets on heads and collectors)better headers w/ heavier guage flanges will prevent this. Good luck! /forums/images/graemlins/thumb.gif
     
  9. Yukon Jack

    Yukon Jack 1/2 ton status

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    Just got off the phone with Dynomax and they faxed me the following specs measured from the middle of the first primary tube to the collector and down from the middle of the primary tubes to the bottom of lowest point of the collector:

    67-87 BBC 2wd headers drop down 16.25" and are 28.44" long on the right side and drop down 17.34" and are 29.60" on the left side.

    73-87 BBC 4WD headers drop down 17.15" and are 32.7" long on both sides.

    70-81 Camaro, 68-74 Chevelle/El Camino, 71-74 Full size BBC headers drop down 10.25" and are 35" long on the right side and drop down 10.16" and are 36.8" long on the left side.

    I previously purchased the 73-87 BBC 4wd headers. I talked to Ed at Mothertruckers (he specializes in 67-72's) and he said he has had excellent luck with the 67-87 BBC 2wd headers on big block 4wd trucks (67-72). The dimensions look like they should work. Wish they didn't hang down so far but with them being shorter will be able to make the bend around the transfer case. The chevelle headers above look great for the amount of drop, but their overall length scares me enough that I think I will exchange my headers for the 67-87 BBC 2wd headers.

    I post how they fit as soon as they arrive.
     

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