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Help with some engine quesions(heads)

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by grindkings, Dec 27, 2004.

  1. grindkings

    grindkings 1/2 ton status

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    This is a new question but same theme. Being that i'm building a new motor. It will be TBI. I'm putting a Holley 670 CFM throttle body and a holley pro-jection manifold. I'll probly put roller rockers as well. My question is...since my motor will be TBI, do i need to stay with TBI Heads(like the one that came stock, and just have them rebuild and ported) or will any heads work fine? Heads are VERY expensive:mad: so i want to go the best route posible. Thanks, -regards brian.
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

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    No you don't have to stick with TBI heads. As cast, they are garbage.

    The problem is that you will be dealing with the different intake bolt pattern, so something along the lines of some pro-toplines will be a good bet.

    I'm not sure about the torquers, etc., but good heads don't HAVE to cost a lot of money.

    There's a lot to be said of the Vortec head chamber design, if you can get that chamber, in a head with your intake bolt pattern, you will be doing good. Just have to research, unless someone knows the part number for the above described off the top of their head.

    If you rebuild stock heads like they should be for a new motor, (new valves, springs, checked/straightened, seals, not including studs if required) they will likely cost you MAYBE $1-200 less than a set of brand new heads, which will be better in the first place.
     
  3. grindkings

    grindkings 1/2 ton status

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    Thanks abunch. I just talked to a buddy of mine and he said he might have some TBI heads off a 1992 GMC. So i'll look into those. Does anyone know the bolt pattern on a Holley Pro-jection manifold. Thants what i'm building around. Regards- Brian
     
  4. Adub

    Adub 1/2 ton status

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    I used Vortec heads and an Edelbrock Performer vortec intake with an adapter plate that let me bolt the TBI to it.
     
  5. aj johnson

    aj johnson 1/2 ton status

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    This route has my vote... vortec heads are the BEST you can get for a budget...
     
  6. imiceman44

    imiceman44 1 ton status

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    I know the Holley projection is supposed to be a retrofit to old engines so it has the old carbed heads bolt pattern.
     
  7. Thunder

    Thunder 3/4 ton status

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    What kind of manifold are you buying? You dont need a TBI manifold with Projection. Holley makes a bunch of different manifolds for projection. Or you can get an adapter plates to bolt the ProJection TB on any manifold you want. It is a very adaptable system.
    I definatly would not use TBI heads or pay money for them when you can get a lot better head. Rebuilding and porting a set of TBI heads well cost you just as much or more as buying a set of aftermarket performance iron or Vortec heads.
     
  8. grindkings

    grindkings 1/2 ton status

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    So what you are say is that like 92` tbi heads won't bolt up to the Helley projection ?
     
  9. dyeager535

    dyeager535 1 ton status Premium Member

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    Just depends on the intake bolt pattern of the pro-jection manifold.

    TBI heads have all eight corner bolts at an angle, just like all previous SBC.

    However, the CENTER intake bolts on *TBI* heads are vertical. There are 4. Older SBC's had the center 4 angled just like the corner ones.

    There are ways to work around these issues, but if you haven't bought parts yet, you might as well buy matching components in the first place, and save yourself time and effort on install.

    Of course, getting better heads that match up to whatever intake you decide to run, is a fine idea as well.

    "Best route" as you say, will be to spend money now on good components, instead of beating yourself up later for wasting money on junk, like stock TBI heads.
     
  10. sweetk30

    sweetk30 professional hooker Premium Member

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    vortech heads

    the v-tech heads are just as good as the old camel humps . and with the 1.94in/ 1.5ex valves thay make lots of tourqe down low. just have the heads worked up for the needed biger springs(stock no good with big cams) to fit and bolt on and go.
    p.s. thay are 64cc chambered heads
     
  11. bigblock44k5

    bigblock44k5 1/2 ton status

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    You can drill the center bolts of intakes to fit either head pattern rather easily.
     
  12. dyeager535

    dyeager535 1 ton status Premium Member

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    Just as good? Try superior in about every respect. :)
     

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