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Old 11-29-2017, 01:48 PM   #1
BurbFam
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15x12 on 3/4 ton

Hello all, new member here. I remember seeing a wheel/rim fitment thread on here, or maybe another site? Either way, I’ve recently picked up a 1991 3/4 ton suburban 4x4. It’s got i believe 3” fender flares but stock wheels. Looks dumb how sunken the wheels look. I found some 15x12s with 3” of backspacing, according to the seller for $80. 1) how far will these tires stick out and 2) is that enough backspacing to clear the calipers? Thanks all and look forward to get to know you guys and help as much as i can!
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Old 11-29-2017, 02:25 PM   #2
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Re: 15x12 on 3/4 ton

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Originally Posted by BurbFam View Post
Hello all, new member here. I remember seeing a wheel/rim fitment thread on here, or maybe another site? Either way, I’ve recently picked up a 1991 3/4 ton suburban 4x4. It’s got i believe 3” fender flares but stock wheels. Looks dumb how sunken the wheels look. I found some 15x12s with 3” of backspacing, according to the seller for $80. 1) how far will these tires stick out and 2) is that enough backspacing to clear the calipers? Thanks all and look forward to get to know you guys and help as much as i can!
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15x8" 6-lug truck ralleys are common for 4x4's. They have 4" of back spacing & clear calipers so the 3" will clear.

The 12" width & 3"BS will extend about 5" from the edge of the fender lip. More than likely that is beyond most common flares. You can determine the 'will they work' on your own. Pull a wheel & verify the back spacing. Hang a plumb bob off the flare & measure the current distance from it to the current wheel/tire combo. Then it's simple math for your answer.
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Old 11-29-2017, 02:29 PM   #3
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Quote:
Originally Posted by SCOTI View Post
15x8" 6-lug truck ralleys are common for 4x4's. They have 4" of back spacing & clear calipers so the 3" will clear.

The 12" width & 3"BS will extend about 5" from the edge of the fender lip. More than likely that is beyond most common flares. You can determine the 'will they work' on your own. Pull a wheel & verify the back spacing. Hang a plumb bob off the flare & measure the current distance from it to the current wheel/tire combo. Then it's simple math for your answer.
Mine is 3/4 Ton so it’s 8 lug. 3/4 Ton calipers are bigger than halfton right?
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Old 11-29-2017, 03:38 PM   #4
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Re: 15x12 on 3/4 ton

15" might not fit over the calipers.
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Old 11-29-2017, 05:00 PM   #5
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Re: 15x12 on 3/4 ton

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Mine is 3/4 Ton so it’s 8 lug. 3/4 Ton calipers are bigger than halfton right?
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Whoops.... Overlooked the 3/4 ton 8-lug portion. I would bet 16's are needed as well.
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Old 11-30-2017, 08:01 AM   #6
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Re: 15x12 on 3/4 ton

Back in the day guys had to shave the calipers a little to get 15" wheels to fit on a 3/4 ton. I contemplated it for a while to get lower tires for truck pulling. I would keep looking for a more normal size wheel. I like 16x10's with 12.50 tires.
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Old 12-03-2017, 09:49 PM   #7
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Re: 15x12 on 3/4 ton

I run 15x10 with a 4in backspacing on my 3/4ton swapped k5 I did have to grind the caliper bracket and smooth the caliper a little bit not much I'd say that the 3in backspacing would clear without any grinding. These are the only good pics i have of them on my rig at the moment.
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Old 12-04-2017, 02:51 PM   #8
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Re: 15x12 on 3/4 ton

Right on. Thanks for help, i ended up finding a set of 16x10 eagle alloys with 315/75 BFG all terrains for $100. Now onto a lift, 6” is what i need to run 35’s correct? With no rubbing and no fender cutting?
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