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Thorley Headers, please help

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by chev4life, Sep 3, 2004.

  1. chev4life

    chev4life 1/2 ton status

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    I just installed my throley headers last night and the ypipe at the collector is hitting (not quite about a paper sheet above) the frame rail. Has anyone had this problem...if so how to fix? I have thoguht about adding a small wedge or even a second gasket between the header the ypipe flange and try to angle it up...just havent had a chance to try it. Any help would be great, want to get this cured this weekend so I can get the collector flange welded to my cat. Thanks.
     
  2. k20

    k20 3/4 ton status

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    Are you sure you got the right ones? When I had my thorley small block headers they just dropped right in, no clearance issues, my big blocks were a little more work, But as I recall my smallblocks were nowhere near the frame. I have however heard of people getting sent the wrong style, check your numbers.
     
  3. chev4life

    chev4life 1/2 ton status

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    They are the right ones, everything lines up real nice...except it is close in one location...but it dumps almost dead straight wiht my stock cat. I am thinking the slight angle decreace from lowering my t-case with the stock "spacers" might be the problem. Just need some ideas on fixing, cause I dont want to cut or bend my frame.
     
  4. Jonny-K5

    Jonny-K5 1/2 ton status

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    i had the same problem on my 89'. it is on the driver side right? i too have the tranny case dropped and i think thats the problem.

    what i did was just take a large adjustable wrench and bend the lip of the framerail down a 1/4 inch or so right where it hits. you dont have to bend it much.just enough to get you about an 1/8 inch clearance. it wont weaken the frame at all.

    its either that or raise the T-case back up and run a CV joint.dont cut it tho.
     
  5. 1-ton

    1-ton 1/2 ton status Premium Member

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    What I did to clear a header one time was to take a die grinder, with a carbon wheel blade, and make two one inch cuts in the frame. I then took a long steel punch and hammer, and bent the small tab I created in the frame down.
     
  6. chev4life

    chev4life 1/2 ton status

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    So guys went the frame way...I am beginning to think that is the only way to do it without bending the headers. I will try the pry session first then hit up the grinder if need be. I am also gonna try to double up the gaskets on the drvr side to get a touch more length, it might lift it a touch also...but will see in the morning when I slide under the beast again. Thanks for the help guys. /forums/images/graemlins/grind.gif /forums/images/graemlins/hack.gif /forums/images/graemlins/k5.gif
     
  7. Jonny-K5

    Jonny-K5 1/2 ton status

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    i dont think youll need to cut it. i wouldnt bother with gaskets either. all you need is enough clearance so it doesnt rub under motor flex. 1/4" should be fine.
     
  8. chev4life

    chev4life 1/2 ton status

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    All fixed. I pulled out the trusty wrench and bent down the lip of the frame, have a good 3/8" between now /forums/images/graemlins/waytogo.gif Got the exhaust hooked up to it and everything is nice /forums/images/graemlins/peace.gif, thanks for the help guys /forums/images/graemlins/bow.gif
     

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