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Torque add on's

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Executioner, Apr 16, 2001.

  1. Executioner

    Executioner 1/2 ton status

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    Torque add on\'s

    Looking for more Torque down low say 2,000 rpms, and something to broaden(flatten) the torque cure from
    say 1800 to 3800 rpms.
    What can I bolt on, take off, swap, ............ect.
    I have a very tired 350 from around 1977, single stock exhust, really the only mod is Holley Pro-Jection, and
    a K&N in the stock air cleaner housing.
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

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    Re: Torque add on\'s

    For the money, a set of new Vortec heads. The valve sizes are perfect for a truck motor...still work at higher RPM's, but help out with the torque down low. Some small tube headers (not sure what they really are called, but the smaller diameter primary tubes) should help out quite a lot as well. A very small roller cam would be another nice addition. Of course none of this is very cheap unfortunately. But its what I'm going to be running, and I tried my best to optimize it for the low end. BTW, I'm using true duals with manifolds.

    Dorian
    My K5 and Chev/Olds tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
     
  3. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Re: Torque add on\'s

    I'm thinking about a set of Tri-Y Thorley headers which are perfect for trucks (designed specifically for low rpm torque) but a little more expensive.
    <A target="_blank" HREF=http://www.thorleyheaders.com/>http://www.thorleyheaders.com/</A>

    Bad Dog

    85 K30 CUCV, 350 TBI, TH400, NP205, D60/C14, 4.56 Locked
    Soon: 4" lift, 40" tires, massive cutting, shorter wb and rear overhang.
     
  4. FWP

    FWP CRS

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    Re: Torque add on\'s

    The best bang for the buck will be in the Cam...........assuming your gearing's where you want it.

    [​IMG]
     
  5. ftn96

    ftn96 1/2 ton status

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    Re: Torque add on\'s

    The cam and an intake definately.

    Will work for beer, parts and tools.
    90 Jimmy 350TBI-700R4-241-33" BFGs-10 bolts w/4.10's
    <A target="_blank" HREF=http://www.nashvillek5.freeservers.com>http://www.nashvillek5.freeservers.com</A>
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

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    Re: Torque add on\'s

    I think cam would be your WORST bang for the buck. Not trying to start a flamewar, but from the factory, GM truck cams were designed for low end torque. Look at aftermarket cams..you can make tons more HP and TQ than factory, but its at an extremely increased RPM, which is exactly OPPOSITE of what you want in a truck, unless the power is in the range you plan to tow with, or what your RPM's are wheeling. Or if you are racing your truck. Might go great on the freeway, but off the line you are going to have a dog.

    Besides, you have to tear the motor apart to get there, and replace lifters, and to be safe, since you are in there, probably pushrods and rockers.

    Changing my previous stance a bit, headers optimized for low end torque would be the best bang for the buck. I personally don't like headers, (due to plugs, wires, starter problems etc) but I can not argue that they are one of the single biggest producers of "free" power that you can add.

    Dorian
    My K5 and Chev/Olds tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
     
  7. FWP

    FWP CRS

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    Re: Torque add on\'s

    Well, Alrighty then...[​IMG]

    [​IMG]
     
  8. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Re: Torque add on\'s

    BTW, I agree with everything Dorian said. Depending on your gears (especially very low gears), a low rpm oriented rv type cam can make a difference but the right kind of headers are less trouble and expense. But, like he said, headers have disadvantages. Prone to leaks, rusting out (some brands/coatings do not), burning wires, can make routine maintenance like changing plugs or starters a pain, can over heat starters, fuel lines, and fuel pumps, can hit suspension components, the list goes on. Thorley seems to have fewer of these associated problems than most.

    Bad Dog

    85 K30 CUCV, 350 TBI, TH400, NP205, D60/C14, 4.56 Locked
    Soon: 4" lift, 40" tires, massive cutting, shorter wb and rear overhang.
     
  9. HarryH3

    HarryH3 1 ton status Author

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    Re: Torque add on\'s

    I gave up a few lb/ft or torque on the bottom end with the cam that's in my TPI 383. It's still way stronger on the bottom end than the stock 350 was, but when it hits the sweet spot in the rpm range.... OH BABY!!! It goes into hyperdrive! [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://ThunderTruck.ColoradoK5.com>http://ThunderTruck.ColoradoK5.com</A>
    It's a great day to be alive...
     
  10. Executioner

    Executioner 1/2 ton status

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    Re: Torque add on\'s

    Cool ! My sweet spot is 1,800-2,800 rpm's. I have 4.56:1 front and rear, TH350, NP203 so my crwal ratio anit to
    HOT, but my cruse rpm's are 2,800-3,200 rpms with the 36x12.5x15 SS TSL at about 30 psi.
    My goal is to get 350min. from 1,800 to 2,800 at those points, and a peak of say 375 to 400 .
    What can I blot on to get these numbers ? I agree as well I don't like header's for all the above reasons and more
    But if you'll think a 400 pair of headers will get to my goal then that a pretty good bang for 150 lbs./ft.
     
  11. dyeager535

    dyeager535 1 ton status Premium Member

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    Re: Torque add on\'s

    Executioner, can you hit me up direct, I have something for you.

    Dorian
    My K5 and Chev/Olds tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
     
  12. HarryH3

    HarryH3 1 ton status Author

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    Re: Torque add on\'s

    I don't think that any external mods will get you to that kind of power output, unless there's forced induction involved. [​IMG] You need to move a LOT more air to get to that level. The cam is step one. Better flowing heads are step two. There is no magic intake or headers that will nearly double the power output of a stock 350. [​IMG] There are just too many internal restrictions that must be addressed first. [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://ThunderTruck.ColoradoK5.com>http://ThunderTruck.ColoradoK5.com</A>
    It's a great day to be alive...
     

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