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Engine Rebuild Question...

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by rem7600, Jul 21, 2001.

  1. rem7600

    rem7600 1/2 ton status

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    Hi All,

    Have a rebuilt 305 with a 2 barrel
    in my 77 GMC. It came stock
    with a 454 but someone had yanked
    it for another project (still crying over
    spilt milk).

    My issue is that at low end I have
    NO power. I know, I Know, It's a
    305!!!! Well, I just feel theres
    something that can be done to cure it.
    It does have power once the RPMs
    get up there a bit. Albeit 305 power.
    This is all I'm looking for in the low
    end. Is there any combination of
    carb/cam/etc. that might allow me to
    get this power down low without spending
    an arm and a leg or doing a complete
    rebuild (which If I do will be done on
    a 350 block)?

    Hoping for answers.

    <a target="_blank" href=http://www.geocities.com/rem7600/>http://www.geocities.com/rem7600/</a>
    <font color=purple>REM7600 - '89 Jimmy</font color=purple>
     
  2. Neil

    Neil 1/2 ton status

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    might try some 1.6 ratio rocker arms instead of a cam swap. this will help a little, but if you don't have the deep gears and convertor to go along, you will only be making higher rpms available. what is your compression ratio? might want to try some 350 heads. a 041,487,044,461,186 or 993 head might work better for you to get some low end.good luck and give some feedback on what you do. bye,Neil

    Neil H. Alabama '78 K5 400ci 4x4 AT,AC,PW Cheyenne. '74 C10 3spd/floor 250ci 4x2
     
  3. Blazer79

    Blazer79 1/2 ton status

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    Check first on your gearing. Maybe they are 3.07s and that's why you don't feel any low end torque. You may want to go with 3.73 or even 4.11, depending on tire size, which by the way, size tires are you running?

    <font color=purple>//////
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    Soon a 454 K5!!</font color=black>
    [​IMG]
     
  4. Mr.Chevy4x4

    Mr.Chevy4x4 1/2 ton status

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    If you are thinking of a head swap, the L31 Vortec heads are the only way to go. You can mail order them from PaceParts.com for just a little over $400. They outflow all previous castings, and with the new combustion chamber configuration they improve flame travel and increase efficeincy. Dollar for dollar they are one of the best engine mods that you can make. Just my opinion. By the way, you will need new self-aligning rockers($50) and a new Vortec style intake($150).

    '85 K5 : Run it til it breaks, then fix it and go again!
     
  5. rem7600

    rem7600 1/2 ton status

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    I believe the tires are 245/75/16. Shouldn't be the problem. Gearing I am not sure of but it came with a 454. Wouldn't such a model be geared low to start? What are costs for re-gearing to say a 3.73 or lower if it is in fact a 3.07? I know, lotsa questions and very few answers... :-))





    <a target="_blank" href=http://www.geocities.com/rem7600/>http://www.geocities.com/rem7600/</a>
    <font color=purple>REM7600 - '89 Jimmy</font color=purple>
     
  6. rem7600

    rem7600 1/2 ton status

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    Neil, Honestly I know very little about what's in there. I see some posts regarding head changes... If I go to that extent I think I'll just do a 350. I've never rebuilt one and I think it would be a good learning experience.

    Thanks...

    <a target="_blank" href=http://www.geocities.com/rem7600/>http://www.geocities.com/rem7600/</a>
    <font color=purple>REM7600 - '89 Jimmy</font color=purple>
     

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