ecir45

iTrader: (1)

I recently purchased a 6 lug with G80 and 3.42s that I'll be swapping pretty soon.

Anyone know if the OBS are the same minus the bolt pattern? The 8 lugs are more common and are easier to find with 3.73s or 4.11s so could play with different gear ratios for fairly cheap.

A spare G80 wouldn't be a bad idea either even though the truck isn't going to be too radical for the time being. Thinking could also use the 8 lug axles for a 5 lug conversion at later date without sitting the truck up.

Richardman1992

iTrader: (5)

The rear axles in the obs trucks are narrower if I recall

1FastBrick

iTrader: (17)

You have some reading to do. https://www.performancetrucks.net/fo...thread-467473/

If you have a 67.5 WMS-WMS overall length 8 lug setup, you can buy 6 lug axles for it.

You will have to modify the brackets though as documented in the link above.

The problem with the 8 lug axles is the hub center is much larger. It would most likely have to be machined off for most 6 lug and 5 lug wheels to fit. I am also not sure if there is enough room to re drill for a 5 lug set up. You would also have to fill alot of holes to do so. I would use new 6 lug axles as they are only around $100 each. They also have a thicker flange then the factory original 6 lug axles.


Good luck on your project and let us know what you decide to do!

ecir45

iTrader: (1)

I have a 6 lug version. Was just thinking for part swapping wise if they were the same. Not that worried about the axle as much as the center section components.

I been through your and the other threads multiple times but didn't pay attention to any 8 lug stuff. Will give them another read, Thanks.

1FastBrick

iTrader: (17)

I hope you have the 4x4 version of the 6 lug.

The internal guts are the same on the OBS 6 lug to 8 lug 14 bolt 9.5 units.

I have found some good stuff in the 8 lug units. I cracked one open that had recently been rebuilt with new 4.10's and a rebuilt G80 unit. Even the oil still looked fresh.

It's the NBS Hybrid AXN that you have to worry about as they have some specific parts that do not interchange with the OBS units. Like axle bearings and pinion seals.

ecir45

iTrader: (1)

Yes came out a '95 Z71. I was hoping the center section were the same because of the reason you stated. I can get a complete rear at our local pulla for a little of 100 so am going to keep an eye out for some better gears than the 3.42 I have now.

Have you ever read of anyone using the OBS 2wd version. Thinking the narrower version might be good with a 5 lug conversion?

1FastBrick

iTrader: (17)

With the narrower housing, You will need special offset wheels to work on a 99 up truck. The also do not make 5 lug replacement axles for them.

Personally, I would Have the 6 lug axles re -drilled. Replacement 6 lug axles are a common part and the only run just over $100 each new. They are nicer than the factory axles by far.

ecir45

iTrader: (1)

When mentioned 5 lug conversion I meant redrill. If going 5 lug you would need new wheels so was thinking the narrower housing would look sweet with a deeper dish rim. Then if ever decided to go ladder bar or 4 link options for a wheel would be better.

1FastBrick

iTrader: (17)

Then it sounds like you're on the right track for what you want.

ecir45

iTrader: (1)

Going to just use the OBS Z71 for the time being with the shocks relocated to the rear for now. If ever go 5 lug I would consider the narrower axle swap.

Thanks for the help.