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power of a 350 with 38's ?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by wheelin247, Jul 20, 2001.

  1. wheelin247

    wheelin247 1/2 ton status

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    power of a 350 with 38\'s ?

    howdy ya doin i plan on gettin a brand new stock 350 and puttin my old edelbroke intake and carb and headers on and i have flowmaster exaust i have 1 ton axles im puttin and and i plan to put 4:88's or 4:56's in there and i was wonder if my th350 tranny if on the freeway those gears would be to high and wined the motor out to much ......and also do u think that it would have enought power to turn 38's with no problem ?>
     
  2. michaelm

    michaelm 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    right around 25-2600rpm @ 55-60 mph
     
  3. Pure Insanity

    Pure Insanity 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    Heres a link to SuperLift's gearing chart. <a target="_blank" href=http://www.superlift.com/gear.htm>http://www.superlift.com/gear.htm</a>the link has a chart and all the ness. math forulas you will need. The chart is based on a speed of 65 miles per hour. I am running 38s and 488 gears also, w/ a TH350.

    Out of 100,000 sperm, YOU were the fastest?? [​IMG]
     
  4. michaelm

    michaelm 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    you should throw a tape measure on your '38s' from centre of wheel to ground to see the actual radius you are working with. my truck @ near 6000# with 8:1 350 4.88s and sm465 is no highway hauler but it is drivable
     
  5. Pure Insanity

    Pure Insanity 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    But on the flip side at speed tires will grow in diameter. Ever watch a top fuel car??? Granted those tires are a much softer casing, but tires do grow at speed due to centrifugal force.

    Out of 100,000 sperm, YOU were the fastest?? [​IMG]
     
  6. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Re: power of a 350 with 38\'s ?

    Tire growth of dragsters is caused by centrifugal force? I thought heat was the cause.

    Tim
    '84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
     
  7. wheelin247

    wheelin247 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    so i would be able to go like 65 on the freeway at like 5000 rpms?..i wouldnt but that would be around that ballpark right
     
  8. fr8train

    fr8train 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    I would think heat AND centripital force would equal expansion of a drag tire.
     
  9. Pure Insanity

    Pure Insanity 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    UUUMMMM......... NO. w/ 4:88's you'll be turning around 2800 at 65. That is a very comfortable cruising RPM.

    The tire growth comes from the centrifugal force, Think of when they do a burn out, the tire snaps up to a much taller and narrower profile. The instant they let off the loud pedal it goes back into the normal shape. And as a side note at the top end of the track a drag slick will be flat on the back side of the tire (to the back of the car that is) It looks really weird!!!

    Out of 100,000 sperm, YOU were the fastest?? [​IMG]
     
  10. wheelin247

    wheelin247 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    does 4:88's give u good power with that 38's off road or should i go a little more like 5:13's ?becuase i do travel and stuff to go to the trails so i need decent for drivin to.
     
  11. Pure Insanity

    Pure Insanity 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    IMO I think the 4:88's will be optimal. They will give good power and good drivability. Did you check the link I put in my 1st reply?? Those are figured at 65 MPH. If its a trail rig go as low as you dare but yours is a driver so figure out what the max speed is youll be traveling and figure it up from that. I personally would not want to be above 3500 for extended periods. The link I gave has all the math formulas youll need to figuer out whats best for your needs.

    Out of 100,000 sperm, YOU were the fastest?? [​IMG]
     
  12. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Re: power of a 350 with 38\'s ?

    Yeah, you're right. I was just at the drag strip Tuesday so I watched exactly what you were talking about.

    Tim
    '84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
     
  13. Pure Insanity

    Pure Insanity 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    Did you see the tires at the big end? They look soo weird!!!

    Out of 100,000 sperm, YOU were the fastest?? [​IMG]
     
  14. lukerz

    lukerz 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    Is there a optimal rpm for 65 mph?
    Lukers

    83 K10 from 76 K5 & 83 C10
    Th350 Np203 355 CID
    31 X 10.5
    Plan on 2" body lift
     
  15. Pure Insanity

    Pure Insanity 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    IMO around 2800- 3200 is best for @ 65 MPH. Any higher and you will prob go nutz listening to the rig at speed! A friend of mine had 4:11's in his camaro, even w/ o/d the car was wrapped up pretty tight for a long haul. It wasnt hurting the car but if you listen to 4000 plus RPM for long enuff thru flowmasters your ears will ring when you get to your destination. You'll still hear the car screaming for hrs!!! which may not be a bad thing really!![​IMG]

    Out of 100,000 sperm, YOU were the fastest?? [​IMG]
     
  16. lukerz

    lukerz 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    What if you are running lower rpm's ?Let's say 2100??
    Lukers

    83 K10 from 76 K5 & 83 C10
    Th350 Np203 355 CID
    31 X 10.5
    Plan on 2" body lift
     
  17. Pure Insanity

    Pure Insanity 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    2100 @ 65!!!! What do you do idle thru town at 30!?! WAY TOO LOW! If you have 38's and your runnin 2100 @ 65 you have 3:73 gears and need to go to a 4:88. IMO Thats if you dont have an O/D. if you have an O/D maybe a 5:13.

    Out of 100,000 sperm, YOU were the fastest?? [​IMG]
     
  18. lukerz

    lukerz 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    I have tiny tires 31's the chart puts me at 2100 at 65mph. Sometime in the future I will get lower gears(waiting for the right deal)
    Lukers

    83 K10 from 76 K5 & 83 C10
    Th350 Np203 355 CID
    31 X 10.5
    Plan on 2" body lift
     
  19. Pure Insanity

    Pure Insanity 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    Oh yea, your sig has your tire size. DOH!! I guess you have 307s. You definately need more gear before you get more tire. Yea you can drive w/ 38s and 307s but it wont pull a worm out of a chickens ass. Definately invest in gears before getting any bigger IMO. Whatever size you go with. (I just used 38 as an example)

    Out of 100,000 sperm, YOU were the fastest?? [​IMG]
     
  20. RESTORE89

    RESTORE89 1/2 ton status

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    Re: power of a 350 with 38\'s ?

    i had 307's with 33's and he is right the thing would not get out of its own way. and it would not even stay in od going up an over pass on the exspressway. however, i think it would top out at about 743 mph lol.
    411's and 33's and it will outrun the wife volvo of the line. you might be a redneck if your wife has a new volvo wagon and you convince her to drag race????????


    It needs a bigger motor.
    what's in it now?
    doen't matter it NEEDS A BIGGER MOTOR
    89 350tbi/700r4h/np208/4.11's
     

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