8.5" B-Body rear into G-Body

[Doober]

https://gbodyforum.com/threads/trying-to-swap-a-b-body-rear-into-the-monte.5002/

I see he hasn't been around in a long time, so has anyone else given this a shot? I'm about to trade an engine stand for an '80s 8.5", so I guess worse case scenario I could just turn around and sell it.

 

[Kennybill]

Pretty big difference in the width. Is it a posi? What's the gear ratio? Being a 8.5 they might be worth something. 1964 to 67 A-bodies are narrower than the 1968-72. Southside Machine use to make a kit to use these housings. Good luck

 

[Doober]

I'm not worried about width, going to have it shortened to stock width (2"-3" overall difference). Not sure of gearing etc., but I'm not worried about that either, cross that bridge when I come to it. The 8.5" B-Body rears are pretty plentiful, so they aren't very pricey. It will also need the brackets transferred over from the G-Body rear. By the time it's done my plan is for it to basically be a G-Body 8.5", with the only difference being the upper control arm length, but I'm not sure how much difference that will make in suspension travel/geometry.

 

[SSpev]

Why not an 8.8? I've been contemplating this for my wagon. $350 kit, arms and brackets. Plus some axels.

 

[Doober]

If I got an 8.8 for free maybe... don't forget the flange on the driveshaft or custom length axles. Once it's done all I need is a pair of off the shelf axles for a G-Body, and if the last thread is accurate it's closer to a bolt-in than any other rear, not counting the shortening and bracket relocation that's typically required for most swaps.

 

[Doober]

Well I picked it up Sunday, biggest part of the swap is done

 

[81cutlass]

Biggest problem is the LCA mounting locations. Thats why 8.8 swaps kinda sorta work but have varied success. The instant center is messed up and is never really fixed.

Interested to see the progress.

 

[Bar50]

If I say the paint is wet, would you touch it to check?

 

[565bbchevy]

Unless you are doing all the fabrication such as the narrowing, adding the brackets etc. I am not sure what the appeal is over getting a bolt in 9" housing that can use your stock control arms and comes with strong axles in the spline count of your choice.
http://www.quickperformance.com/QP-GM-1978-1987-G-Body-9-Inch-Housing-Axle-Package_p_63.html

 

[oldsmobile joe]

i looked at one of these "B" body rear axle once when i had it laying around the garage, i thought the upper control arm mounts (which are cast as part of the housing) were the sticking point. i don't remember the mounts matching a g body or the axle from the 64-72 "A" body cars. i believe they are further apart.
but i will gladly be wrong. we all would love another source for rear axles. please keep us posted on your endeavor.