Figured i would get a better response posting in the truck section, than in the general drivetrain section. What all exactly would i need to convert the front of my truck to 8 lug? Im swapping in either a 9.5' or 10.5" 14 bolt so i'll need to change the front over to 8 lug as well....so im wondering what all is different on the 4x4 front ends between the light duty 6 lug and heavy duty 8 lug.

I've got fabtech lift spindles on the front so if i can retain them and swap to a 8 lug, i'll go with a 10.5". If not, i'll go with a 9.5" and swap out the axels for 6 lug's and leave the rest alone. Anybody know what i'll need to change?

 

Why not just use a 9.5 with 6 lugs on it to begin with? There are a lot of them out there and it is a fairly stout axle as well even though it is a semi floater it is still much stronger than a 10 bolt.

 

Yeah id just upgrade the splines and call it a day

 

Will the NBS discs work on a OBS 9.5" 6 lug rear? I know that the lug patterns are the same, but OBS wheels won't fit on NBS trucks--I'm not 100% sure why, but I think it has something to do w/ the centerbore on the wheel?

I have seen PLENTY of OBS's with NBS wheels, so I guess that the centerbore of the NBS wheel is smaller than the OBS wheel?

 

for what its worth there are converson adapters out there to make the 10.5 a 6 lug

 

Yes but you have to deal with the full floating hub too.

 

I think you just need to put it on a lath and take off a hair.

 

I think its because the NBS rear disc's are larger than the OBS rear brakes. The axle flanges are exactly the same so i dont see why the NBS brakes wouldn't work on the OBS housing. I've looked at my pops 97 3500 duallie with a 10.5" 14 bolt and the housing is identical in all the mounting points, flanges, and shock mounts.

The only thing im remotely concerned about is if the 33 spline 9.5" 14 bolt will be strong enough for what im planning on doing. I know the 10.5" is just a 30 spline, but its alot stronger because its a full floater and the axel doesn't support the weight of the truck. The only 6 lug conversion i've seen for a 10.5" full floater converts it to a semi-floater..and that pretty much gets rid of any advantage except for the larger ring gear. Can anybody contest to the strength of a 9.5" semi-floater? My future plans are for either a cammed and blown 6.0 or a 402/408 stroker and running 36" tires with 5.13's. I thought about a Moser 12 bolt or 9" with 35 spline axels, but i'd have to have new rear brakes and by the time it was all said for i would have about 3g's in a rear end.

I haven't seen any, but is there a company like Moser or something that makes c-clip eliminators for the 9.5" 14 bolt? I've checked Moser's site using there Axel calculator and a 33 spline axel should do me for up to 600 ft. lbs, although i dont know how accurate that is because nothing on the calculator took into effect of weight or tire height, and i don't know if they figure in converter mulitplication. I would deffinitely want c-clip eliminators for the extra insurance just in case.

 

The 9.5 is solid up to 38's or so even in very hard use. You will have no problems with it and 35's no matter what you do to engine. Laso for what it is worth, the 9.5 weighs about 75 lbs less than a 10.5 and has more ground clearance under the pig too and more locker options as well. Not knocking the 10.5 but it is overkill here for what you need.

 

I was beginning to think that it would be overkill as well. I didn't know about the lesser weight though and i thought the housings were the same so i didn't know about the ground clearance either. So exactly what model's am i looking for in the OBS for a 9.5" with 6 lug? And could i use a 9.5" 8 lug rear out of a NBS and swap out the 6 lug OBS axels just incase i cant find a 6 lug 9.5" out of a OBS? I seriously doubt its going to happen, but it would be nice to just find a housing cheap and go from there. I was under the impression that the 10.5" was only used in the OBS 3500 and all diesels from 88 up.

Also this is slightly off my original topic, but is there any options out there for a 9.5" that would hold better than my Eaton posi and still have street manners for a daily driver? The posi for a 9.5" might hold better than the 8.5" so i don't know if it would do the same...but occasionally when i power brake and spin the rear tires, only the passenger rear tire will spin no matter how long i powerbrake it. Other times, the posi works flawlessly. I know i could get a detroit locker for a 9.5", but i've heard alot of stories that they are really jerky and noisy in corners under acceleration.