33x12.5 on K30 without lift

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84K30

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I’m in the market for some new tires. Ideally, I’d like to go with 33x12.5s. Probably going to go up to a 17x9 wheel since I plan to do a rear disc brake conversion in the future. Has/does know if these will fit without rubbing on a stock height K30?

Also, has anyone run rear discs on anything smaller than 17x9s? Personally, I like the stock hubcaps and would reuse them if I knew calipers would fit a 16” wheel.

Thanks,
Eric
 

Frankenchevy

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I have 33s that are about 11.5” wide with no rub on an unlifted cucv. I have disc rear with 16” rims as well. Most kits utilize a k10/20 front rotor and caliper or Cadillac eldorado rear caliper, so clearance on a 16 shouldn’t be an issue.
 

Dysco

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On a k30 you should be fine height wise. Width might be an issue. Backspace of the rims would be a factor.
 

Craig 85

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Here's a couple pictures of my truck. The first is before I bought it. The PO had old school 33x12.50x16.5's on 9.75" wide wheels. It only needed minor trimming on the front fenders. I put a 3" lift on it and I'm running 305/70/16's on a 16x10" wheel (4.5" BS). I know the 305's only have a 12" section width.

Frankenchevy is running a 16x8 wheel with 285/75/16. Our tires are the same height, mine are just wider. Wheel Vintiques makes a 16x10 steel wheel with 5" of back spacing.

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84K30

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I had an issue with 12.5s rubbing the leafs on another truck of mine. Really limited the ability to make U turns etc. Not worth the extra money at that point
 

RoryH19

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Not sure how much difference between a k20 and k30 but without a lift my tires would rub on my k20.
I had 33x12.5xR16
 

Craig 85

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Not sure how much difference between a k20 and k30 but without a lift my tires would rub on my k20.
I had 33x12.5xR16

K30 frame is about 2" taller than a K10/20. My 3" lift on my K30 turned out to be a 5" vs. the 4" I had on my old K20. The 16.5's and the 305's are 32.8" tall. You can see the K30 still sits higher in the front. The rear is about the same as the K20 had a 2" block and a 2.5" add-a-leaf.

K20
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K30
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84K30

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I am not looking to lift my truck. It barely fits in the garage as it is and it'll be parked (hybernating) every year from late November until mid-march to keep it from seeing road salt. I'll probably end up replacing the stock 235/85 with a 265/75 on the stock wheels for now and possibly get wider wheels and tires next go around. Thank you to all who replied!
 

Frankenchevy

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I am not looking to lift my truck. It barely fits in the garage as it is and it'll be parked (hybernating) every year from late November until mid-march to keep it from seeing road salt. I'll probably end up replacing the stock 235/85 with a 265/75 on the stock wheels for now and possibly get wider wheels and tires next go around. Thank you to all who replied!
Do you have 15” or 16” rims? I have 285/75/16 and they’re no problem. Had the same size on my stock width 16” steelies as well.
 

Craig 85

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Since you said you may go with 265/75's, here's how my truck looked prior to the lift with that size tire. Absolutely no issues with them rubbing. Wheels are 16 x 6.5" with about 4.5" BS.

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ali_c20

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I had 33x12.5 R15 general grabbers at on my k5 without lift, no rubbing.
 

84K30

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The wheels currently on my pickup, which I believe to be factory, are 16x6.5. I’ve read that a 7-8” wide wheel is recommended for 265(~10.5 inch) wide tires. However, I’d feel comfortable running them on my current wheels. I’d consider 285s if they fit the current wheels & I knew they definitely wouldn’t rub lock to lock. Thanks for the replies!
 

Frankenchevy

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The wheels currently on my pickup, which I believe to be factory, are 16x6.5. I’ve read that a 7-8” wide wheel is recommended for 265(~10.5 inch) wide tires. However, I’d feel comfortable running them on my current wheels. I’d consider 285s if they fit the current wheels & I knew they definitely wouldn’t rub lock to lock. Thanks for the replies!
My steelies were the same as yours, 16x6.5. I can assure you 285s don’t rub. Here are some pictures of my truck pre-resto. Tires are Yokohama Geolander 285/75-16 on factory 16x6.5 wheels.
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PrairieDrifter

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265/75/r15s fit a stock 1/2 ton with clapped out suspension.
 

Tmich396

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33x12.5x15 on a Stock height Blazer with no rubbing issues.
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