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4.11 or 4.56 with 33's

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by emoo99, May 8, 2003.

  1. emoo99

    emoo99 1/2 ton status

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    4.11 or 4.56 with 33\'s

    i have some 33's and a 700r trans.. i've looked at the www.4lo.com and randy's website at the RPM charts that tell me between 4.11-4.56.. but everyone i talk to around here tells me that 4.56 and 4.11 would give me way too much torque and 3.73's would be about right.. the biggest tire i wanna go is 35's so i'm leaning twards 4.56 but will that be overkill for now? will 4.11's be ok with 35's? i want to be able to go up some pretty steep hills though, since i don't know the "feel" torque wise of 33's with 4.11's do you think it would be ok?
     
  2. MousePowrd

    MousePowrd 1/2 ton status

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    Re: 4.11 or 4.56 with 33\'s

    With overdrive its hard to have too much gear. Get 4.56's, then you will be fine when you put in 35's
     
  3. Hossbaby50

    Hossbaby50 3/4 ton status

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    Re: 4.11 or 4.56 with 33\'s

    If you are going to drop the money to regear axles then I would do 4.56's (I did). The 700R4 will give you the added overdrive to make the 4.56's act like a set of 3.42's or so in OD. It put most motors into a good powerband for cruising and hill climbing.

    Don't waste your money regearing to 3.73's. It is totally not worth it. That is the ratio i had before the 4.56's.

    Personally I almost wish I had went to 4.88 gears in my truck. But I do plan on running 37" tires so that is my reasoning. If you plan 33-35's then 4.56 is a good ratio with a 700R4.
     
  4. jekbrown

    jekbrown I am CK5 Premium Member GMOTM Winner Author

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    Re: 4.11 or 4.56 with 33\'s

    yeah, 4.56s with the 700 oughta work well. Only reason I could see not to doing 4.56 vs 4.10 would be if you were gonna swap axles relatively soon and going to 4.56 cost more (ie full carrier replacement etc).

    j
     
  5. emoo99

    emoo99 1/2 ton status

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    Re: 4.11 or 4.56 with 33\'s

    i think i'm goin to swap axles, it's a heck of alot cheaper.. i got $600 to spend but i heard that 4.56 is hard to find unless it's in a M1008 k5, and i don't know where to look for one of those..
     
  6. k20

    k20 3/4 ton status

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    Re: 4.11 or 4.56 with 33\'s

    i know there was a post w/ a link about where to find m1008's, i did a quick yahoo search and found http://www.govliquidation.com/
    if you dont find anything there with a search (dont have time to really look). Try doing a yahoo search for military surplus auction.
     
  7. zakk

    zakk 1/2 ton status

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    Re: 4.11 or 4.56 with 33\'s

    5.13's. You'll want bigger tires. we all do eventually. There is a really good parable that a friend of mine has, but it's not appropriate for the open forum.

    with 5.13's and 35" tires, you'll be spinning 2241RPM's at 65MPH. that is at the base of the power band of most SBC motors.
     
  8. 84k5

    84k5 1/2 ton status

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    Re: 4.11 or 4.56 with 33\'s

    4.11 or 4.56 should be good with 33s or 35s. Super low gears aren't going to be very strong unless you have 1 ton diffs. You're pushing it once you get past 4.56 in a half ton axle.

    Something else to remember is that almost all 35" tires are not 35" tall. My 33" mt/r were maybe 31.75" when brand new. Makes sure you use the actual height when doing the calculations.

    Another thing is you need to take an honest look at how the vehicle is used. Personally, I don't know anyone under the age of 70 that drives 65 on the freeway. I normally keep the k5 to 75, but many will cruise at 80 or so.

    Good luck deciding.
     
  9. Zeus33rd

    Zeus33rd Smarter than you GMOTM Winner

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    Re: 4.11 or 4.56 with 33\'s

    [ QUOTE ]
    i think i'm goin to swap axles, it's a heck of alot cheaper.. i got $600 to spend but i heard that 4.56 is hard to find unless it's in a M1008 k5, and i don't know where to look for one of those..

    [/ QUOTE ]

    M1008's have 10 bolts with 3.08's. Not 4.56's. 10 bolts, 6.2 diesel, TH400(I think)and 208 t-case. Nothin special about them at all. /forums/images/graemlins/usaflag.gif
     
  10. SUBFAN

    SUBFAN 1/2 ton status

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    Re: 4.11 or 4.56 with 33\'s

    The deeper gears will help that T 700 live longer too....
     
  11. Swanson52

    Swanson52 1/2 ton status

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    Re: 4.11 or 4.56 with 33\'s

    [ QUOTE ]
    with 5.13's and 35" tires, you'll be spinning 2241RPM's at 65MPH. that is at the base of the power band of most SBC motors.

    [/ QUOTE ]

    Well I'll be damned...I had never even CONSIDERED 5.13's before...just assumed they would never be workable on the highway. Evidiently (with the 700), that is not even the case. Is the ~43 to 1 crawl ratio acceptable for most dual purpose rigs (street/trail) that don't see the type of hardcore stuff you do (some rocks, but pretty mild)? Good point...I appreciate the insight. Screw 4.56.... /forums/images/graemlins/thumb.gif
     
  12. Hossbaby50

    Hossbaby50 3/4 ton status

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    Re: 4.11 or 4.56 with 33\'s

    43:1 Crawl is pretty good area for crawl ratio. Most of the AZ guys with doublers are around 41:1 so with the 700/208/5.13's (or 241 case) you are in the cheap doubler range. So you can crawl just about anything you need. And if you don't need that much crawl you run 4Hi. The 700's 3.06 first and 5.13's would work well for most light trail action

    The only thing you do need to consider is:

    #1. This is calculated with a tire that is a true 35" tall.
    #2. 5.13's in a D44 or 10 bolt front is pushing it. (Zakk's 5.13 thing is based on his moto of 1 ton is the only 1)
    #3. When you shift into 3rd gear on the highway at 65 MPH you will be spinning 3200+ RPM.

    So if you cruise faster then 65 or want to accelerate you push alot of rpm's.
     
  13. Swanson52

    Swanson52 1/2 ton status

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    Re: 4.11 or 4.56 with 33\'s

    [ QUOTE ]
    #1. This is calculated with a tire that is a true 35" tall.

    [/ QUOTE ]

    Yes, this is the only reason I may consider 4.88's.

    [ QUOTE ]
    #2. 5.13's in a D44 or 10 bolt front is pushing it. (Zakk's 5.13 thing is based on his moto of 1 ton is the only 1)

    [/ QUOTE ]

    Same issues with 4.88's in a 44 front?
     
  14. Hossbaby50

    Hossbaby50 3/4 ton status

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    Re: 4.11 or 4.56 with 33\'s

    It border line. Some say yes, some say no. Personally I am going to run 4.88's in my next offroad only truck in 1/2 ton axles. But this truck is going to be as light as possible.

    If you don't beat the ever living piss out of your front then 4.88's should be fine. I imagine that a good quality gear will have a higher yeild strength then the stock axleshafts.
     
  15. 89GMCSuburban

    89GMCSuburban 1/2 ton status

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    Re: 4.11 or 4.56 with 33\'s

    Go 4.56. I have 31's with 4.10's and the power is great. OD stays locked up even up hills in big truck. When I get my 36's in, I'm re-gearing 4.88.
     
  16. tecton

    tecton 1/2 ton status

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    Re: 4.11 or 4.56 with 33\'s

    dont plan on driving on highways
     
  17. zakk

    zakk 1/2 ton status

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    Re: 4.11 or 4.56 with 33\'s

    [ QUOTE ]
    [ QUOTE ]
    #1. This is calculated with a tire that is a true 35" tall.

    [/ QUOTE ]

    Yes, this is the only reason I may consider 4.88's.

    [ QUOTE ]
    #2. 5.13's in a D44 or 10 bolt front is pushing it. (Zakk's 5.13 thing is based on his moto of 1 ton is the only 1)

    [/ QUOTE ]

    Same issues with 4.88's in a 44 front?



    [/ QUOTE ]

    Crawlin70 runs 5.13's in his D44/12B. it's a matter of persective. if you have a mild motor and your easy on the gas, it can work.

    If your running a 672 CI motor with 900HP and the only throttle position you know is on or off, your in trouble.
     
  18. bigjbear

    bigjbear 1 ton status Staff Member Moderator

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    Re: 4.11 or 4.56 with 33\'s

    [ QUOTE ]
    M1008's have 10 bolts with 3.08's. Not 4.56's. 10 bolts, 6.2 diesel, TH400(I think)and 208 t-case. Nothin special about them at all.

    --------------------

    [/ QUOTE ]
    That would be an M1009. M1008 has D60 front & a FF14B w/ Detroit rear. They are geared 4.56:1.
     
  19. bigjbear

    bigjbear 1 ton status Staff Member Moderator

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    Re: 4.11 or 4.56 with 33\'s

    With 33s & O/D I would go 4.56:1. For 35s its kind of a toss up. 4.88 or 5.13 is in the the pwr band but you are giving up pinion strength in a 1/2 ton. I have 35s & 4.56 w/ a TH350 and can crusie Atlanta's interstates as long as I stay out of the fast lane. Unless you are very worried about MPG don't worry about spinning that SBC to 3000RPM on a regular basis.
     
  20. fourwheelerjeff

    fourwheelerjeff 1/2 ton status Staff Member Moderator

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    Re: 4.11 or 4.56 with 33\'s

    i am currently building my 88 blazer to run a 5.13 10 bolt front and 12 bolt rear, with 37 inch mt/r's and 35 inch boggers depending on terrain, running a lock right in front and a gov-lok in the rear and crossover steering /forums/images/graemlins/thumb.gif
     

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