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CFM of stock TBI

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by k20, Jun 7, 2003.

  1. k20

    k20 3/4 ton status

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    Just need the CFM of a stock 7.4L TBI unit. Running it through desktop dyno w/ 670 cfm and its makin 558tq at 3500 and 485hp at 5000. Just need the real cfm that that tbi is.
     
  2. Bubba Ray Boudreaux

    Bubba Ray Boudreaux 1 ton status

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    670 cfm is correct /forums/images/graemlins/thumb.gif
     
  3. k20

    k20 3/4 ton status

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    are u serious? I just pulled that # cuz it was the cfm of that holley replacement for the small block. Yes. Beast power then!
     
  4. Bubba Ray Boudreaux

    Bubba Ray Boudreaux 1 ton status

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    [ QUOTE ]
    are u serious?

    [/ QUOTE ]
    Nope. I lied...............


















    NOT!!!!!!! You hit it right on the head.
     
  5. sled_dog

    sled_dog 1 ton status

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    350 is a 500 and 454 is 670, you got it right.
     
  6. SUBFAN

    SUBFAN 1/2 ton status

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    Does the Big Block T.B. just bolt on to a 350?
     
  7. sled_dog

    sled_dog 1 ton status

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    no. the bores are quite different. if you bolt it on you will defeat the more air with the fact that the air will just be hitting the manifold now obstructing the intake. Aftermarket TBs are the same. Aftermarket intakes don't fix it either which you think they would do so you would buy their aftermarket TB. Get your intake holes bored out port them to match the TB and you would be set. I believe besides that its simple bolt on.
     
  8. SUBFAN

    SUBFAN 1/2 ton status

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    I figured I'd have to 'hog' out the intake, but other than that it's just the same thing?

    Shouldn't baffle the computer either?
     
  9. sled_dog

    sled_dog 1 ton status

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    not really sure. I think its more than a simple port job. Never really looked or known the measurements. differenece of 1 11/16" and 2" I believe.
     
  10. Bubba Ray Boudreaux

    Bubba Ray Boudreaux 1 ton status

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    [ QUOTE ]
    Never really looked or known the measurements. differenece of 1 11/16" and 2" I believe.


    [/ QUOTE ]

    Yup. I do believe a computer reprogram is in order to be able to get everything out the swap though.
     
  11. SUBFAN

    SUBFAN 1/2 ton status

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    Just a generic aftermarket chip or????

    I have other plans down the road, should I hold out for a whole custom job?
     
  12. Bubba Ray Boudreaux

    Bubba Ray Boudreaux 1 ton status

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    [ QUOTE ]
    Just a generic aftermarket chip or????

    I have other plans down the road, should I hold out for a whole custom job?

    [/ QUOTE ]

    This is what I would do, and this is just from what I've read on hear and on the GMECM mailing list......

    Either get the software and ALDL cable and do it myself; or talk to people like Turbo City and see what they can do with a setup like this. Stay away from a "generic" chip. They have a general setup and you more than likely wouldn't be able to harness all the possible gains from the setup.

    Just for example, I have an ADS Superchip for the K5 that I very rarely run. It requires premium gas cause it jacks the timing. It has shown very little performance gains.
     

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