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The OFFICIAL 33" tire on stock K5 thread

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by wrathORC, Nov 17, 2002.

  1. wrathORC

    wrathORC 1/2 ton status

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    Two sections, 15x10 and 15x8.

    15x10
    I have 33x12.50r15s on 15x10 Outlaw IIs with 4" of backspacing. I have the heavy duty front suspension (3 leaves and quad shocks) from the factory. The rear droops more than the front.

    I have the chrome trim. I cut it out where the tire was rubbing. I then proceeded to use a block of wood wrapped with a chamois and a hammer to beat in the lip so it didn't hang out. These were aftermarket fenders. When done, I took a pair of channel locks to the right fender at the leading end of the opening to bend the lip some more.

    The only place it will rub is the bottom edge of the fenders (where it curves under at the front and back). The only time it rubs is when I'm turning the right amount, braking hard, and hit a bump. It slops my suspension around and makes the tire kiss the fender. The gutter in front of my house makes it rub. I have yet to make it rub when offroading (but I bet if I had it turned and was going down a rock it'd rub) since most everything I see is stumps, rocker-ruining logs, and mudpits/berms/offcambers. I don't see many rocks.

    Oh, and I have found out that without a bumpstop (hey, it was in the way of my headers) my tire will touch the top of my wheel opening even with a sway bar.

    15x8
    As long as you don't have droopy springs and sloppy bushings they'll fit. My uncle and some of my Dad's friends used to off-road back in the 80s. I have seen pictures of these trucks (and one K5) with 33s on them flexed out. My parents' neighbors friend used to tear his truck apart so often I joked that he should put it together with wing nuts. He ran beadlocks which I didn't understand until I got into ATVing. Anyway, he had a single wheel 1 ton with 33s for the weekend and some kind of skinny tire turning the week (hauled construction trailer). He was hardcore into it, he pulled both sway bars each weekend and put them on Sunday night.



    Moral of the story: 33s on 8" wide wheels with 4" of backspacing will fit as long as you don't have droopy springs or an axle that isn't centered in the hole. Sloppy bushings are a bad omen as well. What does this mean? <font color="red">Since these trucks have been out of production for more than ten years it's a case by case situation as to whether 33s with any rim combination will fit or not due to all the spring sagging, body sagging/shifting, and axle wandering that can happen in this amount of time.</font color>


    My experience:
    31x10.50s on 15x8s (4" bs) fit with a fist's worth of room. 33x12.50s on 15x8s (4" bs) fit with about 1.25" of room. 33x12.50s on 15x10s (4" bs) fit with about .5" of room. I did my testing on my truck with the truck in gear with the brakes on (neighbors are good for something) with the tires turned to the spot where it was closest. On my truck, the closest spot is on the driver's side at the bottom of the fender towards the cab.
     
  2. Bubba Ray Boudreaux

    Bubba Ray Boudreaux 1 ton status

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif
     
  3. wrathORC

    wrathORC 1/2 ton status

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    I know, I should've made the red part real small so then they'd read the whole freakin' thing and find out that there's no definitive answer.

    hehe.
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    Another reason is because some people seem to think that 33x12.5 is the only tire size out there. A LOT more people would have positive experiences on 33" tires if they would use NARROWER tires. Anyone else ever wonder why most 33's rub when turning and flexing at the same time. My 33's NEVER rub, no matter how hard I wheel.

    I've jacked one front wheel up with a floor jack until the passenger side front lifted, and turned the wheel. No rub. Again, springs and amount of flex are going to affect this, but 2" less width is going to solve a lot of problems.
     
  5. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    Sawzall cures all problems. /forums/images/graemlins/smile.gif
    If you leave the sway on you can clip back to the inner fender and it will work on stock 8 inch rims. Some scrub but not bad and not tire shreading.
    I'll sticky for a while and maybe it will stop a few repeat post....probably NOT but what the hey! LOL
     
  6. codeman

    codeman Registered Member

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    Well I just got done deer hunting this weekend and had a chance to test my new 32" BFG/AT's. They are mounted on 15x8 rims with 3.75" of bs. I rubbed big time any time my front axle had to flex. I don't see how 33's are possible on any K5 that touches any real terrain. I plan to trim my fenders ASAP!
     
  7. wrathORC

    wrathORC 1/2 ton status

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    33x12.50s are the least expensive other than 31x10.50s. 32x11.50s cost more than 33x12.50s. When I priced 32x11.50s they cost the same amount as 35s. I don't even want to know what narrow 33s cost.

    Skinny tires are pointless where I'm at. If all you did was PLQ, gravel, and rocks then skinny tires are great. The idea of wide tires is to float over things instead of digging to the bottom. 31x10.50s are useless in sandy loam unless you air down. 33s you can still traverse pretty easily in 2wd. How do I know? Probably because I have a set of 31x10.50s in the basement.

    The Jeeps do great on 31x10.50s though.

    There's got to be a reason why wide tires sell.

    I'm pretty sure my tires wouldn't even rub at the top of the fender well if I had them on 8" wheels. When flexed to the max I'm pretty sure the rubber would be inside of the wheelwell instead of hitting the lip.

    I don't know. I've got 4" springs waiting to go on. Maybe that way I won't have to hose out my truck every time I go wheeling.
     
  8. wrathORC

    wrathORC 1/2 ton status

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    Got any pictures?
     
  9. Bubba Ray Boudreaux

    Bubba Ray Boudreaux 1 ton status

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    You can actually get some flex in Nebraska? /forums/images/graemlins/rotfl.gif /forums/images/graemlins/rotfl.gif
    Actually, I'd like to have more detail. I was running that size on 10" rims before, but never wheeled. They looked cool sticking out like they did, but I can imagine the problems I would of had. With the 8" rims, the tires tuck in nicely and I just worry about wheel wells, but those are coming off.
     
  10. Bubba Ray Boudreaux

    Bubba Ray Boudreaux 1 ton status

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    </font><blockquote><font class="small">In reply to:</font><hr />
    Sawzall cures all problems.

    [/ QUOTE ]

    Yep. Looks like I'm going to 35" here in the next few weeks, but the height is staying the same for $$$ reasons, so my wheeling will be limited, but I'll be fender trimming since that was in the plans. Gotta get that cool prerunner look going and then have the excuse to get it painted next summer.
     
  11. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    I clear 35's scrub free with 2.5 inch rancho springs, 1 inch body lift and 1 inch zero rates with the front axle moved forward 1 inch. I'm only trimmed back to the inner fender. I NEVER scrub and I am running a 15x10 rock crawler rims with 4 inches of back spacing.
     
  12. thatK30guy

    thatK30guy 1 ton status Premium Member

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    The '82 K30 sitting in my yard has the stock springs. Fronts are the 3-leaf type. Tires are 33" BFG's on 9.75" wide whitespokes. Don't know the backspacing though. The very end corners of the lower rear part of both fenders have been trimmed to clear the tire. The rest looks good and appears to clear just fine.
     
  13. codeman

    codeman Registered Member

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    Well I know trimming would do the trick, so that is probably what I will do. I can tell you this, the tires only rub when i am going straight ahead and really get the axle to flex. I have not got them to rub while turning. I do have a digital camera, so I could take some pics. I could email them to you if you would like.
     
  14. Thumper

    Thumper 1/2 ton status

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    Every truck seems to be different. I have 35x12.5s on 10" wheels, a 4" susp, 3" body, 3/4" zero rates, and no sway bar. I have been stretching the truck out lots more lately, and I was rubbing the back of my fender right at the bottom under full stuff (about 1" from bottoming out those RS5012s on the Ford brackets) until I cut the fenders. I trimmed them back about 2" at the bottom to the inner, and now they dont touch at all. Goes to show ya...

    Mike
     
  15. Leadfoot

    Leadfoot 1/2 ton status Premium Member

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    Factors
    Stock springs sagged yet...
    True tire height (usually greatly exaggerated)...
    True tire width...
    Rim backspacing...
    Type of wheeling...

    Unfortuneately it's nowhere near a cut and dry Yes/No answer.

    Simple answer, run them until they hit.
    If they do, live with it, lift it, or chop it /forums/images/graemlins/thumb.gif
     
  16. Sandman

    Sandman 3/4 ton status Author

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    Once you start with the sawsall its hard to stop. And this aint nothing compared to some folks here.

    [​IMG]
     
  17. Chubby

    Chubby Registered Member

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    Ha.......that's pretty smooth work for a sawzall!!!
     
  18. MissGMC

    MissGMC Newbie

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    33's on a stock rig work great. the tread depth on those tires new was 17/32's. if you switched to a 15x10 wheel it would only make the problem worse. the only reason your tires rub is the aftermarket wheels on the vehicle. the original backspacing was 3.75 on the factory rally wheels. the front springs are supposed to have a negative arch. this gives the springs a better ride quaility and more flex(droop) on the front. but in your situation trimming the tips off the inside of the front fenders will stop your rubbing problem, or add leaves all the way around and get 2.5" for $150-$200. /forums/images/graemlins/k5.gif
     
  19. MissGMC

    MissGMC Newbie

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    I run 33's on my Jimmy. At first they rubbed all the damn time, but extra leaf springs solved that problem. I advise you invest in some, they make all the difference. /forums/images/graemlins/thumb.gif
     
  20. homemadesin

    homemadesin 1/2 ton status

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    Re: The OFFICIAL 33\" tire on stock K5 thread

    1972 Blazer CST, bone f'ing stock (except HEI) with BF Goodrich 33x12.5x16.5LT tires. Only one serious off-road experience with it (up over and around Webster Pass in CO) - no rubs, no hay problema. Of course, it is one of the few bone stocker's I've w/o a$$ droop.....
     

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