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Best headers for front driveshaft clearance on a 1 ton? Flowtech?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by cjk3500, Jan 11, 2003.

  1. cjk3500

    cjk3500 Registered Member

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    I have an 86 GMC K3500 Crew Cab. I put dynomax coated headers that were listed to fit on it but the flange rubs on the front drive shaft /forums/images/graemlins/angryfire.gif. It is also very close to the primary pipes. I was looking at flowtech afterburners, they seem to have the primaries up higher? Any suggestions would be great!!

    Thanks.
     
  2. ibrakeformud

    ibrakeformud 1/2 ton status

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    you might want to try looking into the hooker comps.
     
  3. Highlander

    Highlander 1/2 ton status

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    I know how you feel I have the same headers as you and the same problem what I'm going to do is go with Thorley tri Y's I plan on going to a single Exuast setup but so what. I did see where Thorley has headers for 4 and 6in lifts.

    Eric
     
  4. cjk3500

    cjk3500 Registered Member

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    Those look nice! There a little pricy /forums/images/graemlins/frown.gif, but I've heard good things about thorely. How soon are you going to get them? I'd love to hear from anyone that already has them as I need to get a set asap to get my truck inspected. I have to get ones with the air injection fittings.

    Thanks!
     
  5. Highlander

    Highlander 1/2 ton status

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    It will be sometime this summer, I wish it could be sooner but after replacing the t-case and the tranny now the rearend and all that goes with that the Header deal is going to have to wait.
    They are some $$$ but I think it will be worth it in the long run.I my case I'm going to get rid of my duel ex. and go to a single 3in. With the single I can have room around the front shaft and the tranny pan right now I have about 1/4. this all change for the worse when I put the 205 in.

    Eric
     
  6. cjk3500

    cjk3500 Registered Member

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    I have a 205 now and duals. There is very little clearance. I tried grinding down the flange and taking off some of the lumps on the weld of the driveshaft but it still hits and grinds in 4 wheel drive on a flat surface, I would hate to see what would happen off road! I have two options now: find new air injection pipes to put back in the factory stainless shorty headers and drill and tap them for new studs (broke 4 out of 6) or get the thorleys. I like the second option but I know how you feel I recently replaced the motor and trans in my truck too. I'll let you know if I do get the thorleys and include some pics for you.
     
  7. dammit32

    dammit32 1/2 ton status

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    Summit Racings part # DTE-364Y8 HEADERS CHVY BLAZER 73-91
     
  8. BlackDog714

    BlackDog714 1/2 ton status

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    I had the same problem until I changed my motor mounts!!! Its worth swapping them out, it made all the difference in the world! BTW, I love my DynoMax Coated Headers.

    Oh yeah, I also have an 86 GMC K3500. Its a standard cab SRW with a 454.
     
  9. dammit32

    dammit32 1/2 ton status

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    I 'd like to add a dumb question here.

    They sell one set with a heat riser and one without.Which do i need for my 91? no smog tests here yet

    is that the hot air port that goes to the air cleaner ?

    btw the part # above is for a 4-6"lift
     
  10. Highlander

    Highlander 1/2 ton status

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    You have some of those OEM stainless shorty headers /forums/images/graemlins/smile.gif I thought about those but to find a set in a junk yard would be hell and costly. The Thorleys have the AIR stuff and a O2 bung. I was going to go that way as well just in case the fine state of Colorado finds out I have no Emissions on my 83 /forums/images/graemlins/blush.gif
    So if you get them please do take pic's I wonder if your SS headers would clean up good......

    Eric
     
  11. cjk3500

    cjk3500 Registered Member

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    I only have a puny 350 so the headers are different. I don't think motor mounts would help me unless they lifted the engine up about an inch.
     
  12. cjk3500

    cjk3500 Registered Member

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    I think the OEM headers would probably clean up good. They are just that used stainless brown, but I guess they could be polished up, the only problem is the huge air injection tube manifolds that go with them. I'm just trying to find a source for new air pipes because I tried to remove them and one of the pipes broke. I have a GM part number, but I'm not sure if it's correct. Most people have never even heard of the OEM truck headers. Does anyone on the board have the parts microfiche?
     
  13. Highlander

    Highlander 1/2 ton status

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    Thats what I would think take them down to a shop and have them cleaned up some what. they could turn out to be pretty neat looking.
    As for the AIR stuff have you tried Checker or Auto Zone? I would think you should find that stuff there as they rot out pretty easily.

    Eric
     
  14. thatK30guy

    thatK30guy 1 ton status Premium Member

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    Last I heard, Flow Tech and Dynomax are something like the same headers, parts, etc., just a different name.

    I ran Flow Techs on an '86 SWB K10 with a 350. Those headers were the worst POS's I've ever seen. /forums/images/graemlins/angryfire.gif They hit the spring shackles and bolts, on both sides, and I tried to make them fit by heating and bending the tubes. Nope, no luck. Screwed up the headers even more. /forums/images/graemlins/angryfire.gif Total cost: $85. You get what you pay for with cheapo headers.

    I replaced those headers for Hedman Hedders. Fit perfect and everything cleared on the first try. Today, they are still in that truck. Even my '85 K30 with a 454 has Hedman Hedders.
    I paid $150 for these new Hedmans for the 350. Hedman makes 2 different headers for the SBC in the GM trucks. One is a shorter version, not the block hugger, but just closer to the starter. This one I did not use. I got the other one thats longer and sits at the location of most major line of headers have, around the shackle area.
     
  15. Chris Demartini

    Chris Demartini 1/2 ton status

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    <font color="blue">I run Flow-Tech 88-98 shorty headers and a 3" single exhaust. It has very good clearance and sounds better than dual. Check my member album for pics

    Shorty headers are way better for our application than full-lengths IMO
     
  16. 79Beast

    79Beast 1/2 ton status

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    Flowtech headers are CRAP...I'll never buy another set. I have already swapped my set out once under warranty because they cracked where the four tubes come together. They also won't seal at the collectors.
     
  17. cjk3500

    cjk3500 Registered Member

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    Thanks. I was looking at those 88+ headers. If I can't get my OEM headers worked out I'll keep them in mind.

    I see your in Dumont NJ. Do you know of any good places to off road in northern NJ?

    Thanks!

    P.S. Nice Blazer, that crash sucks!!!! /forums/images/graemlins/frown.gif
     
  18. cjk3500

    cjk3500 Registered Member

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    Thanks for the info. It looks like any of the cheaper headers don't hold up too well. My OEM headers are looing better and better. /forums/images/graemlins/smirk.gif
     
  19. dyeager535

    dyeager535 1 ton status Premium Member

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    I looked those headers up a year ago or so, and even with the best price they were over $200/side. Ouch /forums/images/graemlins/smile.gif

    I can probably get you the part #'s for those tubes, or double check for you if you like. Another option is to just use pipe plugs (brass if you can find them) and remove the AIR pump, although doing so usually renders the AIR pump bad for future use. For some reason sitting disconnected tends to make them go bad.
     
  20. cjk3500

    cjk3500 Registered Member

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    The part number I have for the air lines is 10045322. I think it is correct because I just went on the rockauto page and they have a pic of the ac delco part with that gm number and they look the same. Now I just have to drill out the broken studs. I guess if I see another set of these in the junk yard I should snatch them up! /forums/images/graemlins/grin.gif
     

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