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33's and 3.42 ok?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by solowookie, Apr 18, 2001.

  1. solowookie

    solowookie 1/2 ton status

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    33\'s and 3.42 ok?

    Hey,

    I just check my gear ratio according to the factory code, and it reads GU6 for an 89... (3.42 evidently)

    Anyway, I want to run 33x10.5 BFG at's on my stock susp. Will I have a rubbing problem or gear ration problem?

    If I can get away with this then I can get my truck painted quicker... I really don't want to up to 35's until I swap axles and do the lift (all about the same time)...

    <font color=blue> Jeff </font color=blue>

    [​IMG][​IMG]
     
  2. wayne

    wayne 3/4 ton status

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    Re: 33\'s and 3.42 ok?

    If you keep it on the street you should be ok. I heard some guys say they were running 33s on the stock set-up.

    <A target="_blank" HREF=http://jamonline.homestead.com/fromthegroundupK54x4/89Jimmy.html>http://jamonline.homestead.com/fromthegroundupK54x4/89Jimmy.html</A>
    <font color=blue>Happy Trails<font color=blue>
    <font color=blue>Wayne<font color=blue>
     
  3. 87 mid canada k5

    87 mid canada k5 1/2 ton status

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    Re: 33\'s and 3.42 ok?

    You won't be using that o/d anymore!

    Denis
     
  4. Esteban86K5

    Esteban86K5 1/2 ton status

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    Re: 33\'s and 3.42 ok?

    Like canada said, you won't have O/D anymore with 3:42 and you'll be a slug off the line. I run 4:10's and 33's and love it. Also you won't be able to leave the blacktop without rubbing. I rub my 33's but I only run 2 1/2in lift.

    <font color=blue>Esteban</font color=blue>

    <font color=red>SEMPER FI TO MY BLAZER
     
  5. solowookie

    solowookie 1/2 ton status

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    Re: 33\'s and 3.42 ok?

    don't have an auto I gotta sm465... [​IMG]

    <font color=blue> Jeff </font color=blue>

    [​IMG][​IMG]
     
  6. DeesleK5

    DeesleK5 Registered Member

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    Re: 33\'s and 3.42 ok?

    I have a 91 k5 with 2 in suspension lift and 33's. I like the set up but there is a little rubbing say when you are turning and hit a decent bump. I rarely notice any rubbing and i go offroading here in dallas quite a bit. I think you will be fine with two inch and 33's, but i know alot of guys with 4 inch and 33's that like that set up

    Will
     
  7. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    Re: 33\'s and 3.42 ok?

    I think you'll be ok with the 3.42's and 33's. The 4 speed is your saving grace. I run 36's and 3'73's with the 4 speed and its a hair tall but liveable. As far as rubbing, unless you run more backspacing than stock they will rub. Mudhog gets away with 33's and no lift because of his backspacing, but his truck is definitely the exception. Trim your fenders a bit at the rear corners and don't get too carried away wheeling it and you should be OK for the short term.

    Rene

    [​IMG]<A target="_blank" HREF=http://jules.coloradok5.com>http://jules.coloradok5.com</A>
     
  8. dyeager535

    dyeager535 1 ton status Premium Member

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    Re: 33\'s and 3.42 ok?

    I'm running the 33x10.5 BFG AT's, 3.42's, 350, SM465, and stock wheels.

    First off, it is NOT a slug off the line, as much as a 4800lb vehicle can not be called a slug. The clutch isn't overtaxed, I can still put it in 1st (not low) on flat ground, without giving it gas, and idle away. I can hit 60 (and higher) before the on-ramps to the freeways end, and I can surpass 85 quickly with ease. I have to admit I have no clue what parts are in the 350, but I run it on 87 octane and have been averaging 12mpg city/freeway, (and I still need to lean the carb out for cruise)so its not too radical. Q-jet with factory true duals (used to be a diesel truck)

    The tire rubbing I personally believe has to do with the springs and wheels more than anything else, ESPECIALLY with the 33x10.5's. Backspacing was mentioned as being a problem, and it definitely can be. Soft springs (as in MAYBE the 2 leaf/5 leaf rears) and harder off roading, MIGHT allow tire rub with the stock wheels. Mine is nowhere near close, but that is with 3 leaf fronts/6 rear of unknown age. I tried jacking up one tire, and with the wheel lock to lock, there is no way the thing can rub...the suspension gets too stiff to let the tire go into the wheelwell far enough.

    Dorian
    My K5 and Chev/Olds tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
     
  9. solowookie

    solowookie 1/2 ton status

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    Re: 33\'s and 3.42 ok?

    well, thats what I'm trying to do, just get by for the mean tie.... ultimately I want to run 35's and a 4" lift so I'll probably have to do a little trimming anyway...

    I can get 4.10 gears for this thing, front and rear, for $300.00. I want to change the rear axle though, probably to a 12 bolt so I'd like to not put any money into gears etc. until I go to a 12 bolt...

    <font color=blue> Jeff </font color=blue>

    [​IMG][​IMG]
     
  10. Emmettology 101

    Emmettology 101 3/4 ton status

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    Re: 33\'s and 3.42 ok?

    You'll be ok, I ran 35's and 3.08's for a few years..

    Mike - <A target="_blank" HREF=http://emmett.coloradok5.com>http://emmett.coloradok5.com</A>[​IMG]
     
  11. 90K5

    90K5 1/2 ton status

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    Re: 33\'s and 3.42 ok?

    I have 33's and 3.42's. Its no speed demon, I'm going to 4.11s soon....hopefully.

    90K5

    See my truck at <A target="_blank" HREF=http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502>http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502</A>
     
  12. solowookie

    solowookie 1/2 ton status

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    Re: 33\'s and 3.42 ok?

    hey guys, thanks for the info...

    I started looking for a 12 bolt today, and I found one for $50.00! [​IMG]

    The spider gears in the back are bad or the ring and pinion, but hey, for $50.00 I think I can afford to fix a few things on it!

    <font color=blue> Jeff </font color=blue>

    [​IMG][​IMG]
     
  13. dyeager535

    dyeager535 1 ton status Premium Member

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    Re: 33\'s and 3.42 ok?

    Look into the parts before you buy, the spider gears alone for a 10 bolt last I checked were around $80...

    Ring/Pinion? Probably about $300 to have them installed correctly with parts included.

    $50 is good to have spare axles and drums etc though!

    Dorian
    My K5 and Chev/Olds tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
     
  14. Emmettology 101

    Emmettology 101 3/4 ton status

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    Re: 33\'s and 3.42 ok?

    Ya, 12bolts are usually cheap!

    Mike - <A target="_blank" HREF=http://emmett.coloradok5.com>http://emmett.coloradok5.com</A>[​IMG]
     
  15. solowookie

    solowookie 1/2 ton status

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    Re: 33\'s and 3.42 ok?

    I called the biggest salvage yards in Utah, and only one place had one... It has 3.08 gears and they wanted $350.00 for it. Everywhere I called told me they hadn't seen a 12 bolt around for a LOOONG time... bummer...

    Looks like I may be paying the $50.00 and picking up the unknown...

    <font color=blue> Jeff </font color=blue>

    [​IMG][​IMG]
     
  16. Emmettology 101

    Emmettology 101 3/4 ton status

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    Re: 33\'s and 3.42 ok?

    Do you need a complete 12 bolt, or do you just need parts?

    $350 for one is too much unless it has all new gear, bearings, etc....

    Mike - <A target="_blank" HREF=http://emmett.coloradok5.com>http://emmett.coloradok5.com</A>[​IMG]
     
  17. lehtola

    lehtola 1/2 ton status

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    Re: 33\'s and 3.42 ok?

    I've got a 4" lift with 35's and run 3:42's. not a problem as far as I'm concerned. My gas mileage has improved a little too. But I don't do any hardcore off road stuff. As far as power...I've not noticed too much of a difference. I however, will be changing out the engine to a hp 350 or 383 within a year and of course change the gears to 4:56. Just wanted to let you know I've not experienced any problems...(yet).

    1990 GMC Jimmy 350/TH700R4/NP241/10 bolts, 4" skyjacker lift, 35x12.50R15 BFG All Terrains on 15x10 AR Baja's, Flowmasters.
     
  18. solowookie

    solowookie 1/2 ton status

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    Re: 33\'s and 3.42 ok?

    thanks for th info...

    I think the only place I really need the gear change is for steep inclines... I do drive a LOT of steep inclines though, and considering the only time I wheel is with my wife and kids that is something I'm not willing to go without... I would want it just for the power increases too.

    Since it's almost the same work I'd prefer to do it all at the same time.

    talk about a BIG change... I'll probably do my gear change, powertrax, lift, and new tires / wheels all at the same time!!! It will be like a completely new K5... lol

    <font color=blue> Jeff </font color=blue>

    [​IMG][​IMG]
     
  19. dyeager535

    dyeager535 1 ton status Premium Member

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    Re: 33\'s and 3.42 ok?

    Western WA is pretty darn hilly compared to most parts on the east coast. At 60mph, I am able to easily climb any grade on the freeway....these are some that you'll see the 4 cylinder mini-vans struggling on, so they are not just small bumps...long drawn out affairs.

    I have no problem cruising on flat ground in 3rd at 25mph either. (but thats a slow as I want to go in 3rd...thats almost idle RPM's)

    40mph on an extremely steep grade (guessing 8-12%) doesn't really require a downshift to 2nd, but I usually do, just to keep from flooring the thing.

    Dorian
    My K5 and Chev/Olds tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
     
  20. Blazerblk

    Blazerblk Registered Member

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    Re: 33\'s and 3.42 ok?

    I need something cleared up for me. I have an 87 K5 with a 700R4 and 3:42 gears and a stock 350. I can use O/D after 50, and when I take off from the line I don't have a problem leaving other cars behind. I also have 33's. I estimate 0-60 7-8 seconds. maybe 9. I know my truck isn't magic or special. I don't have hard time going over 90 either. But, the only problem that I have is towing something over 2000 lbs, up hill and staying at 70mph. Please help me understand. Thank you
     

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