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what Cam for Vortec heads?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by sinchphoto, Jan 28, 2002.

  1. sinchphoto

    sinchphoto 1/2 ton status

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    I have an engine sitting in the garage that's going in my blazer. Its a 350 with vortec heads & I'm looking to slide in a cam,lifters,pushrods,rocker arms and valve springs. Anyone wanna suggest a cam? smog doesnt matter, looking for the maximum output that will work with the heads. I went to a shop today and they suggested somewhere around a 270.
    any thoughts anyone?
     
  2. chevyracing

    chevyracing 1/2 ton status

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    Depends on which Vortec heads you have. If they are the stock ones you can't go above a 460 lift I believe. You have to have the heads machines and use different springs to go bigger. I think the problem is the guides. Scoggin sells the ones that have been machined already for a few bucks more than the Chevy Dealers stock ones.

    John

    Like to go sloppin' 'round in da mud in a rapid fashion....=)

    <a target="_blank" href=http://coloradok5.com/gallery/albun31?&page=1>BLAZER PICS</a>
     
  3. slider

    slider 1/2 ton status

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    Call Comp Cams tech line and they will get you the best bang for the buck. Very helpful people and killer cams. They will ask you alot of questions like gear ratio, what you have done to the motor, headers, Bolt ons like intake and carb size etc.
     
  4. marv_springer

    marv_springer 1/2 ton status

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    I'm running Vortec heads on a 355 that I built about 1 year ago. Went with a "Summit" cam that measured 204/214* @ .050 with 112* lobe separation. Installed it advanced 4* and I love it! Smooth idle, lots of low end, and runs to 5000 rpm nicely. Oh, and no probs with emissions either.

    Marv
     
  5. dyeager535

    dyeager535 1 ton status Premium Member

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    Good idea to talk to some "pros" about cam selection. It's not all about "max power", especially with a truck. Do you wheel (not mud) a lot, and thus need low end? Manual or auto? again more low end, IMO, is more important for the manual, since you don't have a converter helping you out. How about exhaust? Headers or manifolds? Duals or single? Dual pattern cams typically work better with restrictive exhaust systems, and sem to make more power overall inb most cases, even with a "good" exhaust setup. Intake? Carb CFM? All of that plays into cam selection (or should) and is something that an "expert" with a cam company, should be asking you.

    I second that 204/214 cam, I'm going roller with mine. With the roller version, I'm up over 400ftbs at 2000RPM. Not much to speak of for upper end, but that cam (actually the whole engine package, which the cam should compliment) should really help that big truck move out from a stop light, and cruise with great mileage.

    As was stated, .450 is supposedly the max lift with stock Vortec springs, funny thing though, some of the Ramjet motors from what I've heard use Vortec heads, and the cams are over .450 lift. There are springs made to go up to .550 lift without machine work on the Vortec heads, I believe I posted that part # here awhile back. In the same post, I also believe I wrote that I know someone that was running right around .480 lift with stock Vortec springs (and running it hard) and eventually snapped a stud, which I would attribute to a faulty stud, not the springs or lift.

    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
    Why insist on counting when the ring gear has the tooth counts stamped in?
     

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