Camber after NBS 8lug and 9.25 swap

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JayMB

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I'm doing this on mine but reaming the balljoint holes on the GMT800 knuckle to the bigger GMT400 balljoint size so I can keep stock lower control arm.

If the GMT800 lower control arm is longer/shorter that's probably the problem.

You can buy offest bushings for the upper control arm for cheap at Rockauto that should give you a little bit of leeway on camber.

How bad is it now? And in what direction?

This is not a super uncommon swap to get the better two piston GMT800 Calipers and discs that slip over the hub bearing units onto GMT400 HD trucks (which have rotors pinned to the back of the hub flange with the studs from behind, and only single piston calipers with smaller brake pads and much less swept area).

I'm using outer tie rod ends from a 2wd C10 that I reamed my spindles to fit. They fit the stock GMT400 adjuster sleeve (it's a common size for older GM vehicles, 11/16" iirc).
 

Steve A

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How does it look compared to the 800s caster? Have you thought about maybe switching your upper arms side to side to gain a little extra caster?
 

98 Chevy Swag

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This swap can be done a I have the same swap in my truck but with a 6 in bed lift and had a problem with the caster. I fixed mine with more offset camber bolts for the upper control arms and that fixed my problem
 

98 Chevy Swag

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This was the original set off when I went with the 8 lug hub and knuckle and had he 8.25 dif everything worked fine after I got the upper control arm caster bolts with alittle more adjustment I wanna say they are moog. New set up is pretty much the same just with new 9.25 front diff and dropped down 2.5” so cv’s are perfectly flat. Can take pictures if anyone is interested. Anything can be done if you want to put the time and effort into this swap but sas swap is better and easier. Just went this way for the time being so I can have same lug pattern and larger disk brakes on all four corners
 

b454rat

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Ive read it's not hard to do, but just want a visual or something that shows what how and where the mounts need to be cut to put the 9.25 diff in. I want to do this to mine, but think I'm slightly ahead of other swaps. I'm 99% sure I have 3/4 ton uppers on mine already. The rear mount is spread to the back, and when measuring and comparing to the 3/4 upper, got the same measurements. I have a pic on my phone of the upper. I have 90% of the parts to do the SAS, but for now just want toget it going. Yukon has been sitting for a while, and prolly gonna need brakes, calipers inless I can brake the bleeders free. So if I have to spend money on brakes, would rather do it once with the 8 lug stuff. I can get the swap parts cheap from a local yard. Only thing that would take money or extra time is if it anything needs to be reamed. From what I've read, if get donor parts from a 99-00 2500, nothing needs to be reamed.

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orbit

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I like this swap, keep going! There is an upper control arm that fits gmt800s with extra adjustment in the ball joint. It really depends on the upper control arm you have right now. From your picture it looks like you have a 3/4 ton front lift installed on a 1/2 ton. Assuming you bought it like that, I'm not sure what the previous owner was doing. Hopefully when you do all the work you can clean it up a bit and make sure it's all strong.

The control arms are on Rockauto, and allows up to +-3 degrees camber and +-1.5 degrees caster. The adjustment is in the ball joint housing. Set your Cam bolts in the middle and start with the ball joint set in the middle and move from there. AC Delco 45D1398 or Mevotech CMS5011237 both are made by the same manufacturer.

Offset bushings as previously advised will work too, but with those you have to completely remove, rotate and press back in to adjust.

Depending on how far off you are you might need a combination of both bushings and ball joints. But also be aware with the additional height the ball joint creates, you'll need larger diameter wheels or less backspacing than stock.
 

b454rat

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It’s a rancho lift, bout all I know. Bout it lil over year ago, trying to fix **** n get it going. Needed motor n tranny, now need to finish bleeding brakes....
 

Supercharged111

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Those are definitely half ton uppers, but I too want to see you figure it out. So I can copy you. :D
 

b454rat

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But why is the drop mount wider? When I measured the ones on the truck, the measured the same as 3/4 ton...
 
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