6 lug to 8 lug on Denali 6.2 4WD

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BeenChevy

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Anyone know what's involved converting from 6 to 8 lug hubs, front and rear? Looking to put together a list of parts from my boys with knowledge on the topic.

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OR VietVet

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Wouldn't you have to swap in 3/4 axles and all the adaptation that goes along with it? Or, spacer/adapters that have an 8 lug pattern that will bolt to the existing 6 lugs.

Why are you doing this?
 

OR VietVet

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I am sure that is not all it will require. Yes different mounting, shafts and u-joints, brake line set up? May require different master cylinder for the brakes? Shocks? Etc........
 

randeez

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arent the 2500 rear axles leaf sprung?

you either swap the axle, having to weld on spring and arm mounts.

the 9.5sf you can get set up for 5 link, you may be able to find 8lug axle shafts for it, need to do all the brakes from older HD truck maybe.


not too sure how youd get 8lug up front. the hubs with 8 lugs need a different spindle (4 bolts) not sure if the older 8lug hubs would bolt to the gmt900 spindle

lots and lots and lots of "it could work" but dont think anyone has ever really tried to go 8lugs with out already having a serious offroad truck and planned on fabbing everything anyway
 
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BeenChevy

BeenChevy

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Lot of on/off ice travel with a wheel house/toy hauler, tugging around a large food truck, boats, and too large of family.. long trips.

Just looking to do something different and beef things out a bit more. Looking to pull out the level and go 4-6" as the front suspension needs overhaul.

Wouldn't convert to 2500 as it'd be too heavy. Have a local shop here for carbon drive shafts. Waiting on spohn to come out with some delsphere parts. Wanna crawl this thing through 2' of snow like it's nothin catch fish and then hit the highway
 

swathdiver

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Lot of on/off ice travel with a wheel house/toy hauler, tugging around a large food truck, boats, and too large of family.. long trips.

Just looking to do something different and beef things out a bit more. Looking to pull out the level and go 4-6" as the front suspension needs overhaul.

Wouldn't convert to 2500 as it'd be too heavy. Have a local shop here for carbon drive shafts. Waiting on spohn to come out with some delsphere parts. Wanna crawl this thing through 2' of snow like it's nothin catch fish and then hit the highway

Ben, IMO I don't think you need them for that, too over kill or as some might say, a solution in search of a problem.

Check out Duraburb's Youtube videos. He used an adapter to go from one to the other but my memory fails me now as to which way. Whoever made them though was mentioned.
 

CMoore711

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Yeah I don't see a reason to go from 6 to 8 lugs, you're not gaining anything unless you completely convert to a 2500HD suspension and drivetrain, which is doable but is a tremendous amount of work. Based on what you've described you're trying to do 8-lug or an HD conversion is not needed.

If you're plans include a 4-6" lift, then just make a wheel and tire choice that fits your needs and you're set, no real reason to convert to 8-lug.
 
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BeenChevy

BeenChevy

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Thanks for talking sense into me guys. Was a stoned thought for sure. While it'd 'look' cool with 8 lug AT4 wheels on er - I can't add the extra weight of a full conversion unless I throw in a diesel too and stay OFF ice.. it'd make more sense at that point to throw the body onto an HD platform.
 

OR VietVet

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I think it makes more sense to just buy another rig with the platform you want. The only thing that is hard about that is the money out of your pocket.
 

swathdiver

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Thanks for talking sense into me guys. Was a stoned thought for sure. While it'd 'look' cool with 8 lug AT4 wheels on er - I can't add the extra weight of a full conversion unless I throw in a diesel too and stay OFF ice.. it'd make more sense at that point to throw the body onto an HD platform.

The refined frames of the GMT-900 trucks were already stronger than the heavy-half tons of the previous generation GMT-800s. Those had 8 lug wheels like the Ford 7700s but they were not popular because they really were not needed, did not provide any additional appreciable capability. The 9.5" or larger axles only makes sense with higher horsepower applications or 40:1 or lower gearing for crawling and off-road competitions, like Truck Night in America! Miss that show!
 

randeez

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Thanks for talking sense into me guys. Was a stoned thought for sure. While it'd 'look' cool with 8 lug AT4 wheels on er - I can't add the extra weight of a full conversion unless I throw in a diesel too and stay OFF ice.. it'd make more sense at that point to throw the body onto an HD platform.

i mean you're headed in the right direction but i doubt you need 8 lug axles (10.5/11.5 r&p) in the rear, i dont follow the 4x4 sections so i dont know the sentiment on a "built" 10bolt for big tires,or the 9.5 sf 14 bolt out of a 2wd escalade/denali

front i would just leave the 8.25ifs, a good lift kit that keeps the cv axles in line and you prob wont have any issues. wait until it breaks then weigh upgrading it.

the newer denalis have a selectable tcase right? not the awd with abs controlling slip mess?
 

Chert_Detective

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Lot of on/off ice travel with a wheel house/toy hauler, tugging around a large food truck, boats, and too large of family.. long trips.

Just looking to do something different and beef things out a bit more. Looking to pull out the level and go 4-6" as the front suspension needs overhaul.

Wouldn't convert to 2500 as it'd be too heavy. Have a local shop here for carbon drive shafts. Waiting on spohn to come out with some delsphere parts. Wanna crawl this thing through 2' of snow like it's nothin catch fish and then hit the highway

What Spohn parts are you looking for?
 

Fifty

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I think the easiest way to do this is see if the hub/bearing in the ifs 2500 will mount to the 1500 knuckle. if it does then there is your 8 lug front. You may need custom shafts if the spline count or diameter is different.

In the rear, see if you can find our axle in an 8 lug version and swap the shafts.
Or have a set of shafts made that are 8 lug and redrill rotors.

but all this is going to do is spread the load of the wheel accelerating during torque a bit. Not entirely worth the effort.

youd be better off getting an rcv 300m front shaft and cv (934 conversion maybe) if you want more strength.
Then out back see who makes a 40 spline axle and diff and keep the 6 lug.

the wheels are hub centric and you won’t gain much if any load carrying ability of a 6 lug vs 8 lug only swap.
 

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