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Ok motorheads

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Stomp, Mar 5, 2002.

  1. Stomp

    Stomp 1/2 ton status

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    I need some parts help. What kind of parts do I need to buy to build a sbc 355 4-bolt main putting out 250-275 HP. What size cam and all that should I be looking at. Thx
     
  2. mudrunner78

    mudrunner78 1/2 ton status

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    the #'s your looking for can be done without any major mods, look for a small duration cam(suggest call comp cams or whichever) a good dual plane intake (edelbrock preformer) and if you want some vortec heads, and headers. this combo with the right cam will easily make the power you want, just make sure everything is in good working order. Jesse
     
  3. 55Willy

    55Willy 3/4 ton status

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    250? thats a stock Vortec motor
    or even a warmed over TBI motor.
    for that kinda numbers get some vortec heads, a dual plane intake and a 4x4 comp cam, great low end.
    Even stock heads will make that.
     
  4. Stomp

    Stomp 1/2 ton status

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    So basiclly what ya'll are saying is its all in the cam pretty much. Will I have to bump up my compression ratio? Will a stock bottom end work or will I need to upgrade anything? I already have the headers, Edelbrock Performer dual plane intake and Edelbrock 600 cfm carb. I was thinking about the Summit #1103 cam which is 272/282 or should I go to a #1107 292/302, or would that be too much?
     
  5. twenty_below0

    twenty_below0 1/2 ton status

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    the #1103 looks pretty good but I would go with the Comp extreme 4x4 cam MUCH BETTER, worth the extra few dollars and especially for your application, summit is good but the quality is worth the dollars, or even a Crane Kit for 150.00 with the lifters.........Comp has had some problems in the past few years with the lobes going flat, I have ran them and NO problems but others have had problems, suppose to be fixed though..........good luck
     
  6. Jmask

    Jmask Registered Member

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    The cam and the heads. If your hotrodding then you'll want you cams power band somewher from 2000-5000rpm or even higher. If your wanting to tow or 4wheel, you'll need off-idle torque to push that beast over rocks and stuff so you'll want to lower move the powerband to off-idle - 4000rpm. If you have a solid bottom end bored .30 over, and use the vortec heads or even the vintage(I personally like vintage iron) stock heads that chevy put out with the big ass intake ports(camel hump or Fuelie heads) with a strong cam, you can't go wrong. You'll be amazed at what you can accomplish keeping everything as stock as you can. The only aftermarket products I would suggest to you are the intake manifold, carb, cam, and maybe headers(if your motor is too hyper-she needs to breathe right-but don't spend too much)
    That just my .02
    Sorry for the long post
     
  7. 55Willy

    55Willy 3/4 ton status

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    my brother took a stock truck motor and threw in the largest cam the local parts place had, bolted on a swapmeet high rise single plane intake with a holley 600 and got 300 horse. stock heads and bottom end. It ran his truck to a 14.4 @ 98 burning out over half track. he then went back and got trickflow heads with a matched cam with springs, he now has over 400 with forged pistons..all standard bore.
    Also the motor that is in my car has a 72 camaro 350, 2 bolt with a dual plane intake with a holley, with headers and the 292 lunati cam I have 350-375 horse. but these two motors are mid to high r's and a truck should be more of a low to mid power band to get the thing pulling hard.
     
  8. Stomp

    Stomp 1/2 ton status

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    I am thinking this one is about right;

    Specifications:
    * Advertised duration: 262 intake/270 exhaust
    * Duration at .050 in. cam lift: 218 intake/226 exhaust
    * Gross valve lift: .462 in. intake/.480 in. exhaust
    * Lobe separation: 111 degrees
    * RPM range: 1,300-5,600
    * Excellent response, good mid range, noticeable idle
     
  9. Jmask

    Jmask Registered Member

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    That may be a little too much for your truck if it wieghs alot. But other than that, It's fine
     
  10. ftn96

    ftn96 1/2 ton status

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    A freshened up stock motor with a new cam, headers and K&N air breather kit will give that ball-park speaking
     

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