a-body 12bolts rear axle into a g-body?

[nictheking]

i've see a control arms kit to fit a a-body rear axle like chevelle, cutlass, GS at
http://www.umiperformance.com/301519?category_id=53
anybody have try this swap? the only thing different is the position of coils spring emplacement on the axle. but a little work will correct that... and the rear axle is 3" taller than a g-body rear axle but wheels with more backspacing will be right if this kit is good, it will be a cheaper way than buy an GNX rear axle or an aftermarker unit

 

[pontiacman469]

Iceman knows his sh*t:
http://www.maliburacing.com/iceman/G-body 12-bolt uppers.html

 

[TBRtat2]

if you decide to do it, and you still want to drive the car on the street, I would rescomend Control arms with hiem joints instead of the rubber bushings, they will eliminate some of the binding issues with the 12 bolt.

Or you could change the mounts on the 12 bolt, to match the mounts on the 10 bolt. that would let you use the stock control arms.

 

[joe_padavano]

Or you could change the mounts on the 12 bolt, to match the mounts on the 10 bolt. that would let you use the stock control arms.

The problem is the upper control arm mounts, which are integral to the center section. You can't change them.

More to the point, have any of you folks priced A-body 12 bolt axles lately? Sorry, but the correct-fitting G-body aftermarket axles are cheaper. Why does everyone want to do this half-@$$ed method? (Of course, I need A-body axles for my A-body cars...) :wink:

 

[TBRtat2]

They can still be cut off, and different ones put on it, I have done such a thing for cars before. But you need to make sure you brace as needed.
I supose you could change the mounts of the frame side, but i suspect that will take more work adding the needed bracing.
And if you go that far, you might as well go with a true 4 link.

And the price of the axels depends on where you go, there is a junk yard near me that has them cheap, depending on how many they have. Hell iv seen them cheaper then the g-bodys before.

 

[joe_padavano]

They can still be cut off, and different ones put on it, I have done such a thing for cars before. But you need to make sure you brace as needed.

It's a cast iron center section. Not impossible, but certainly not as easy as changing the tabs on the sheet metal axle tubes.

I supose you could change the mounts of the frame side, but i suspect that will take more work adding the needed bracing.
And if you go that far, you might as well go with a true 4 link.

Again, at what price? If the whole intent is to do this cheaply, these extra parts add up fast. Even the aftermarket suspension arms necessary to make this swap cost several hundred bucks. Also, don't forget the price of new rear wheels with the necessary offset. And while most people do not value their time when doing something like this, the reality is that it DOES take time and equipment.

And the price of the axels depends on where you go, there is a junk yard near me that has them cheap, depending on how many they have. Hell iv seen them cheaper then the g-bodys before.

True 12 bolt A-body axle housings (as opposed to the Type O housings with 12 bolts on the cover but ten bolts on the ring gear) start at about $200 for a bare housing. If you can get them for less, you'd better grab them. Complete 12 bolts with posi and a decent ratio regularly sell for at or above $1000.

 

[shotgun]

Wow, the responces here are all over the board.

My 78 Cutlass has a 68 12 bolt from a Chevelle for strength (625hp 600 Ft #).

It is not narrowed, just get the right offset rims. 30x9 slicks just fit.

The lowers are tubular with heims, but they are not needed, stock lowers bolt in .

The uppers are adjustible Metcos, again not needed, but "fixed" Southisde Machine type uppers are needed to get the right offset.

A number of companies make clones of them.

I can't give a honest answer on the spring perches because my rear was in another gbody when I got it but they are moved by the previous owner.

For the street, using Poly in the lower arms.

On the upper use stock rubber in the "ears" and either poly or heims on the frame side.

If you go the heim joint way, make sure they are greasible and do it once a month.

Here my half-@$$ed set up.

 

[TBRtat2]

I have seen complete true 12 bolt rears go for less then $200.00
and i have seen complete 8.5" 10 bolts go for much higher then that.

And beside my first recomendation was to use the control arms with the hiem joints (eliminates most of the binding issuse with the a-body rear in a g-body car, because the angles on an a-body mount are different).
the changing of mounts was just to show that there are more options then just control arms to make the rear work, but you do need to know how to weld.

And as far as cheaper routes, anything you do that is cheaper almost allways means more work and/or time.
Like changing the mounts on a 12bolt will be more work, but you wont have to buy the control arms, you can use stockers, but they should be plated for strength.
You could also do the same with a 9 inch ford, weld on some mounts, and use the stock arms.

But i would like to ask, what kind of power are making, that you feel the need for a 12 bolt? Or do you just want to say that you have a 12bolt rear?

 

[nictheking]

I have a chevy 406 flat top piston, big cam around 400hp and 400 lb tork but if i want more HP i will have the rear end and tanks for your responses. in my province(quebec, canada) i can have a 12bolts a-body for 200-300 buck, a GN 8.5" is like $1600 and a complete moser rear end is like $2500. i think a a-body 12bolts would be a great choice i will save like 1000$ minimum (control arm kit included) it will help to buy a 700r4

 

[TBRtat2]

Just try to remember what you get the rear from, it will make getting things like brakes a lot easier.