i bought a 12 bolt posi rear at a swap meet 10 yrs ago ,i stored it but i'm cleaning my garage and i want to sell it, everyone wants to now what it is out of, what it would easily bolt right in to, and how do i find out. all i know is it is a gm coil spring rear and it measures aprox 48 inches from inside of backing plate to inside of backing plate and aprox 54 outside to outside. are there numbers to run, where are they and who would run them .thanks johnny chevelle:clonk:

i bought a 12 bolt posi rear at a swap meet 10 yrs ago ,n stored it but i'm cleaning my garage n want to sell it, n everyone wants to now what it is out of, n what it would easily bolt right in to, n how do i find out. are there numbers to run, n where n who would run them thanks johnny chevelle

I'm not sure the answer to your question, but I'm looking...
What part of the country you in?
I might be interested...

long island new york where r u thanks if u can b helpful n hopefully u r close

stop with the r, u, b, n crap. That is too hard to read. The word is AND not N.

Do you have any pictures? What kind of suspension is it? Does it have lower control arm mounts, are the ears on top of the pumpkin? Is there a place for a panhard bar to attach? What is the width of the rear? There should be numbers on the rear. Look closely. Any of these answers would help us narrow it down. Good luck, Brett

I think that's a new record for the most useage out of the letter "n" in a single paragraph!

i bought a 12 bolt posi rear at a swap meet 10 yrs ago ,n stored it but i'm cleaning my garage n want to sell it, n everyone wants to now what it is out of, n what it would easily bolt right in to, n how do i find out. are there numbers to run, n where n who would run them thanks johnny chevelle

You need to take pictures of the brackets, the cover area, spring perches and measurements (axle flange to axle flange).

The "casting" numbers might get you a certain year range, but there were several designs (Camaro, Chevelle, Full-size, Nova) that came out in the same year. The "stamped" numbers will differentiate some too, but not sure if some codes were used for more than one year...

For the Chevelle, a "Chevelle/A-body" rearend will swap, but there are some minor differences that might affect tire clearance, etc...

Impala/fullsize will NOT work in a Chevelle due to different suspensions/brackets, and they are wider...

Camaros and Novas used leaf springs, and can not (at least reasonably) be adapted to Chevelles... '65-'67 Chevelle rears can easily be converted to 67-69 Camaro by welding on leaf-spring perches...


There are two other "12-bolts" that are completely different:
1) GM/Chevy "truck" 12-bolt. A completely different rearend that just happens to have 12-bolts...

2)There is also an early 70's Oldsmobile "12-bolt" that WILL physically bolt into a Chevelle, but is a relatively weak and undesirable rearend (almost worthless). Just happens to have 12 bolts on the cover, but the cover is different...

stop with the r, u, b, n crap. That is too hard to read. The word is AND not N.

Do you have any pictures? What kind of suspension is it? Does it have lower control arm mounts, are the ears on top of the pumpkin? Is there a place for a panhard bar to attach? What is the width of the rear? There should be numbers on the rear. Look closely. Any of these answers would help us narrow it down. Good luck, Brett
sorry i am new on a computer.it is a coil spring rear .the rear is approximately 48 inches from inside of backing plate to inside of backing plate,and about 57 from outer stud to outer stud.it has lower control arm brackets and upper control arm brackets.when you say panhead bar do you mean swaybar,if you do i didn't see one.both shock mounts are in the back of the rear.it says gm12 on it but i didn't see any other #'s but i am going to power wash it tomorrow and try to get a picture of it. is this helpful and thank you for trying to help me :clonk:

how would i add a picture from my pictures in my computer to this tech guestion

Should be a casting number, date code, & an assembly code. I would start there. You can probably download a photo to your showroom easier than posting one on the thread.

I don't know of any Chevy rear end that is just 54 inches wide. The narrowest Chevy car rear end was the early Nova, and it was 58 inches wide. You need to post or email some pictures.

well inside to inside is 48 inches outside of stud to outside of stud is aprox 57 inches .the cover is scalloped,:clonk: what about a chevy vega

sorry i was in a rush

The Vega had a 7.5 10 bolt.

well i guess the best thing i can do is find the #'s take a picture tommorow and get to the bottom of this thanks:clonk:

This post certainly didnt turn out to be a classified ad now did it?:sad:

no a brain stormer that hasn't been figured out yet i sent some pics to members they wouldn't upload on this sight so maybe one of them might get an idea

Well you got me. I have never seen one set up like that before. It is a Chevy car 12 bolt, but I don't know what it came out of. The brackets look original in the pictures, but it's hard to tell for sure. It looks like it has the axles retained by the axle bearings instead of c clips. I need more pictures from other angles.

thanks for all the help everyone . a guy in the area had a vega and it matched perfectly he said it is out of a chevy vega gt or a mail truck that was converted but welds looked all original. he offered me 300 for it .is that a good deal or am i selling it to cheap .he said only a serious vega guy would need it, is it worth more to them because it is a rare rear or less. im glad we were able to figure it out with all the help i've been getting thanks to everyone

No Vega ever had a 12 bolt from the factory. They all had the 7.5 10 bolt. This rear end might have been modified to fit a Vega, but it isn't original. Someone could have removed the factory brackets from a Vega rear end and welded them onto this 12 bolt. That doesn't explain the axle bearings though. I don't know why a car 12 bolt would have been used in a mail truck either.

Im Not Sure But The Guy Told Me He Heard A Rumor That It Was The Right Length That You Just Had To Weld The Vega Brackets On But He Was Talking About The Very Tiny Mail Truck They Use Posi Cause Of The Snow,what About The Vega Gt That Only Came Whith A 10 Bolt To Cause The Welds Do Look Original,so Do You Think Its Good If I Sell It For 300 Or Should I Ask More Cause It Fits Right Into The Vega.

I haven't been under any mail trucks, but it makes no since for them to have the car 12 bolt. As far as I know all of the mail trucks had Dana rear ends. All Vegas had the 7.5 10 bolt (GT, Cosworth or whatever). No regular production Chevy car 12 bolt ever had those housing ends and brackets on it. I suspect that some racer or chassis shop built this rear end to fit a Vega because it isn't like any other that I have seen.

If I had a Vega I'd give you $750 for it.

$500 would be a gift IMO.

Providing it's in good shape and brakes are intact.

What is inside it?

you would do very well if you put those pictures on ebay. you may be surprised what it goes for. do not sell yourself short. tom

i guess i gave this vega guy a nice early christmas present i gave him the rear for 400 ,i hope i can get deals like that for my chevelles