Rearends help

[RockSS]

I went to the drags friday .. The New England Oldsmobile club rented the track for the day... sorry no pics I was a little busy playing crew. Anyway I was talking to a guy that had a monte SS (bad *ss) so I looked quick under the back of his car and there was a 12 bolt. So I asked what it came from and he said 68-72 chevelle but it was a little wide and pointed out how his wheels didn't have a lot of dish...(lots of backspace). I found this list of rearend widths

"Which rearends can be swapped into the 78-83 G-Body
The stock 78-88 A/G body rearend housing (housing flange to housing flange) is 52.125". Here is a list of other common rearend dimensions:

Body Style Housing Width
64-67 Chevelle 54.250"
68-72 Chevelle 55.250"
67-69 Camaro 54.250"
62-67 Chevy II 52.125"
70-81 Camaro 55.375"
82-92 Camaro 55.750"
93-up Camaro 59.250"
68-76 Nova 54.250"
78-88 A/G Body 52.125"

So I know the leaf spring rears dont bolt in but other than the width being a little wider are the mounts in the right place this guy said he just got the 12 bolt offset upers and use boxed lower... if this is correct then that opens my search for rears I dont mind going with a little more backspace .. if all else fails I can always narrow it .
I just want to know if the coil spring rear will just bolt in? 8)

 

[kornball426]

I was told yes but you have to use adjustable upper control arms because the mounting brackets that are on the housing on the top are at a slightly different angle and the adjustable control arms have ends that swivel on one end which gives you enough wiggle room to make them line up.

But I haven't seen it for myself.

And I don't know if the spring perch/pocket things are in the same place they might have to be moved I'm not sure. I'm sure someone else will come along with the info you want. :lol:

 

[RockSS]

Thank you for your reply ... I really thought there would have been more responces ... I'll just have to locate 1 and see if they will just let take measurments

 

[Chris Van]

I'm not sure about the adjustable uppers allowing enough room for the offset but I do know that you can buy the offset uppers to install an A body rear. Everything else will line up.

 

[JBreu]

I have a '69 Chevelle 12 bolt in my rear...I bought the 12 bolt swap kit from UMI and it went right in...( also had a 79 Monte years back with a '72 elky rear, used stock control arms then) ......... I have 15x10 wheels now and will be switching to the 15X8 wheels with 4.5 backspaceing. Oh yeah, I never touched the spring perches either.......My car is at transmission shop at the moment or I woulda posted some pics of it!! 8)

 

[RockSS]

Thanks Chris, Thanks JBreu. I appreciate the responces, I now know i can keep my eyes open to other rears ... I just cant justify spending all that money on a bolt in 9" for a tuned up street car that will go to the track once in a while. I know some of you think the 7.5 is ok and it would be since I had it built, new eaton limited slip posi new 28 spline axles all new bearings and hardware. But I dont like how loose the posi is I have a friend that builds rears and he said we could tighten it up but I would have to buy all new springs that go inside and take it all apart. Anyway thanks again

 

[LS1GN]

The bolt pattern for the wheels is different too. 5 on 5 rather than 5 on 4.75 IIRC

A friend keeps suggesting an 8.8 from a Mustang (there's a kit for those too) but I like my stock rims

 

[pontiacgp]

I have a '67 Chevelle 8.2 in my rear...I bought the 12 bolt swap kit from UMI and it went right in and Napa sells a conversion U-joint...and to switch out the springs on an Eaton isn't difficult

this is what it looks like with a 16x8" rim with 4.5" backspacing

 

[84cutlass383]

how much is the UMI kit?

 

[pontiacgp]

$189

http://www.umiperformance.com/catalog/i ... th=8_60_68