Thorley Headers Y-Pipe Fitting Problem...56K Beware

Discussion in 'The Garage' started by stkcode, May 6, 2007.

  1. stkcode

    stkcode Registered Member

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    Ok....these headers where suppose to fit a 1991 Chevy Suburban 5.7 1500, 700R4 2wd, but theirs issues here...

    I called Thorley before hand, talked to Nick and verified that the 367Y3-C (ceramic coated), was the correct part number for this truck, then ordered them from Summit.

    The 376Y3-C is for burbs/blazers/trucks without AIR injection and without heat riser (the butterfly flap on the passenger side exhaust).

    Some of these pictures are a bit out of focus...sorry for that. I use this camera for distance pictures....so a 135MM lens really sucks for close up pictures and is a real pain in the arse to focus on something thats 2 feet away. :whistle:

    So....here we gooooo....

    First issue...a heat riser came with it. Hmmmmmm...not suppose to come with one.

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    Next issue, the oval port gaskets provided for stock port heads? Eh? :doah: Shouldn't these be square port gaskets or at least D-port gaskets?

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    Slider piece that slides into the y-pipe alone does not clear the transmission dust shield (inspection cover).

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    2 of the 3 bolts holes on the driver's side collector don't line up the the holes on the y-pipe. The y-pipe needs to be rotated a 1/4" clockwise, but can't cause it is already hitting the dust shield. :confused:

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    The piece that slides into the cat, is 6" too short. The cat is in the factory position as the truck had the factory cat when I got it. I replaced it with a high flow unit...the factory y-pipe was left intact. Ok, this can be an easy fix as well, just have a muffler shop make me a longer one.

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    Last issue...end of collector on y-pipe collector does not clear heat shield flange between the flange and the transmission. Ok, this was an easy fix, just cut the heat shield flange off, but the instructions mention nothing of the sort.

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    Well...I know I'm getting old, but does anyone else think Thorley messed this order up? The y-pipe doesn't fit right....it's too short, hits the dust shield, hits the heat shield flange and 2 of the 3 driver's side collector bolt holes don't line up. The heat riser seems like a big ticket that this order has been foo-barred.

    The headers fit great....the y-pipe doesn't. This doesn't seem like a direct fit as advertised to me. :(
     
    Last edited: May 6, 2007
  2. supersize75k5

    supersize75k5 OrganDonorRacing.com

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    return the y-pipe,

    get a recomended sho to build the y pipe..then get it coated
     
  3. CDA 455

    CDA 455 3/4 ton status

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    ^^^^^What he said.
     
  4. dleroy43

    dleroy43 1/2 ton status GMOTM Winner

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    I bought the edelcrap shorty "bolt in headers" a few years ago and they had a smaller 3 bolt flange than what my stock had and wouldnt fit. I finally installed them last summer couse I need to get a new Y pipe built for my dubbler. Smog stuff still isint hooked up correctly couse the are differnt sizes/ angles. My o2 still doesnt work eather( was replaced with a heated o2)
    Good luck to you getting it to all work another owner of the missmached yeared burb
     
  5. stkcode

    stkcode Registered Member

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    Ok....I thought I'd post a follow up to this. I got a hold of Nick and the box got mis-labled (so the order was foo-barred). Thorley sent me a slightly longer passenger side connector piece which is suppose to be correct for the 367Y3. But, I'm still having the same problem. The y-pipe still hits the dust shield.

    The problem appears to be either the y-pipe driver's side 2.5 collector flange or the 2.5 collector flange on the driver's side header (take your pick) was not aligned correctly. If the y-pipe 2.5 collector flange was rotated a 1/4" clockwise, it looks like it would work fine.

    At any rate, Thorley wants to just give me my money back...but I already spent money on custom looms and copperseal gaskets. Plus, they appear to be the only CARB approved (yes...the fun emissions joy :mad:) full length headers, for this particular year. BTW...I serious doubt the smog station would even know, but in CA it's illegal to modify the pipes before the cat (or so I'm told).

    So, I'm going to ask Nick if they can send me the same y-pipe, uncoated and without the 2.5 collector flange welded on. I'll fit the bastard in their, align it myself, then weld the flange to the y-pipe. Hopefully it'll work out ok.
     

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