[-DA]

what's the value of an original posi 12-bolt rear end out of a first gen?

i've never been too worried about how original certain parts are on my '67 Firebird but i blew up my 10-bolt and happened run across this 12 bolt. long term plans could be to sell it to someone who needs it for a nice, correct restoration. i'll be building a 9" or d60 eventually so a 12-bolt could be a worthy investment until then... thoughts?

-Dave

[guccieng]

i sold my 3.08 one-legger that came out of my '69 camaro for 300 bucks a few years ago. probably could've fetched more if i really tried. the posi rear ends were going for 700-1000, complete and with desirable stamping for the true ss cars. i would say a complete 12 bolt w/posi and a desirable gear would go for 600-700 bucks, easy, much more if it were all original and coded to something special.

[limejudge69]

Original 12 bolt posis are selling for 1500-2000 depending on the year and gear. Try camaros.net for real world pricing. 3.31-up ratios are the most desirable.

[nashcar]

As limejudge69 says, $1500 seems to be the going rate.

[RAJ7395]

Sold my restored 69 Z-28 3.55 12 bolt for $2000 several years ago. I picked up a 68 firebird 400 earlier this year and would like to find a first gen 12 bolt for it.

[-DA]

thanks for the input! i haven't been able to pull any numbers off it yet but i'm told it's out of a 67 or 68, mid 3's gearing, factory posi, with rebuild drum brakes and new pinion seal. my ballpark guess was gonna be between $1000-1500. it's sitting at the restoration shop i work for but haven't looked at it yet.

i've got a 9" sitting in my garage i could use but it still needs narrowed, gm lug pattern axles and brake setup fabrication work. if i don't wind up wanting/needing this 12-bolt i'm sure i could help someone on here (like you, RAJ) acquire it. i'll check it out some more to find out exactly what it is.

-Dave

[ramair2]

Why didn't 67-9 L67 (ram air) first gen birds get 12 bolts (esp when hi po 1st gen camaros did).

i dont get it.

[D. Rustin]

I didn't think first gens ever came with 12 bolts ?

[keith k]

Originally Posted by D. Rustin

I didn't think first gens ever came with 12 bolts ?

Birds, no. Camaros, yes.

[b-man]

If you're looking to unload it anytime soon, this guy needs your 12-bolt:http://www.pro-touring.com/forum/showthread.php?t=63413

[ramair2]

Yeah that was my point. I realize 1st gen birds (even ultra hi performance ram air birds) -didn't- come with 12 bolt. My question was, and still is, why not? Doesn't make any sense, especially when 1st Gen Camaros did.

===
" Why didn't 67-9 L67 (ram air) first gen birds get 12 bolts (esp when hi po 1st gen camaros did).

i dont get it."

[guccieng]

here's one for a grand:

12 bolt camaro rear end - $1000 (fair oaks)

--------------------------------------------------------------------------------
Date: 2009-12-15, 10:13PM PST
Reply to: sale-xbgu5-1512330573@craigslist.org [Errors when replying to ads?]

--------------------------------------------------------------------------------


1968 camaro 12 bolt gear ratio? $1000 916 995 2442


Location: fair oaks
it's NOT ok to contact this poster with services or other commercial interests



PostingID: 1512330573

[b-man]

Originally Posted by ramair2

Yeah that was my point. I realize 1st gen birds (even ultra hi performance ram air birds) -didn't- come with 12 bolt. My question was, and still is, why not? Doesn't make any sense, especially when 1st Gen Camaros did.

===
" Why didn't 67-9 L67 (ram air) first gen birds get 12 bolts (esp when hi po 1st gen camaros did).

i dont get it."

The Chevy 10-bolts with C-clip axles were inferior to the BOP 10-bolts with bolt-in axles used in the Firebirds. The 25-spline pinion gears were a weak point in the Chevy rears compared to the 27-spline BOP pinion. Chevy had to use the 12-bolt rear because their 10-bolt rears were very weak.

The best versions of the BOP 10-bolt rears had nodular iron housings and heat-treated heavy duty axles, along with strong 4-pinion posi differentials. Not a lot of these rears were used and they're pretty rare just like the Ram Air cars they were used in.

They were deemed to be strong enough, these really were a good strong 10-bolt rear end. Much better parts were used in these than in the common gray iron housing BOP 10-bolts with standard axles and 2-pinion posi units.

[-DA]

i pulled the stamped id numbers off the axle tube today which read: PI 1205 G with an E underneath all that. so, it appears to be a '67/'68 3.55:1 Eaton Posi 12 bolt made on Dec 5 by the Detroit Gear and Axle plant. The center section casting date wasn't legible. it looked like it was covered with a few thick coats of paint making the numbers smoothed over. blasting it would probly make it legible but it's not mine!...yet.

at some point a bracket was welded to the passenger side but was torched off. the rear end as a whole is in decent shape cosmetically although the center section has it's share of axle grease/dirt caking. i was told that mechanically the rear end is sound as they took a look through it when the pinion seal was replaced. it's also got newer parking brake cables and new drums. oh, and a chrome diff cover... +10 HP!

i'm hoping he'll take $1000-1200. if not, i guess i'll be helping one of y'all get it! I'll post some pics of it for those of you interested in buying it if i don't take it home.

-Dave

[Kurt S]

That's a 67 axle. It will have monoleaf mounts.
Too bad the radius rod bracket was cutoff - 67 axles can sometimes pull some extra $$.

I'd like a picture of the axle code. No hurry.

[-DA]

Originally Posted by Kurt S

That's a 67 axle. It will have monoleaf mounts.
Too bad the radius rod bracket was cutoff - 67 axles can sometimes pull some extra $$.

I'd like a picture of the axle code. No hurry.

No, there was a second bracket (non-factory) welded to the passenger side axle tube which has been removed. I believe the stock radius arm bracket is still there. It's 13.5" or so off center line... does that sound right?

A few pictures would certainly help clear this up... tomorrow over lunch hopefully.

-Dave

[Kurt S]

Here's some pics of the bracket:
http://www.camaros.org/radiusrod.shtml

[-DA]

ok, here are a few pics of the rear end. you can see where the extra bracket was welded on and cut off. i discovered the other side had one too but it was ground all the way off so you don't notice it. i found out today this 12 bolt lived under a 30something dodge street rod for a bit so who knows what the bracket was for. my guess is shocks/dampers.

in the last pic you can see the stock radius bar bracket and the spring perch. the perch is wide like for mono leafs but it's got a side spacer stuck in there now as though they ran multi's on that dodge street rod.

if you're looking at more than the F-body 12 bolt.... there's another 12 bolt behind it out of a chevelle (i think) and yes, that's a flat head ford motor on-end behind it.

-Dave

[Transamric]

Great thread guys. Just one minor tweak. According to my early Chevrolet MPC P&A 30, a 'G' manufacturers code rear axle was manufactured by the Chevrolet Gear and Axle Plant. A 'W' code was for Warren Gear, 'B' for Buffalo Gear & Axle, & a 'K' was for McKinnon Industries.
Don't see a code for a Detroit plant, at least not in the '66-68 time frame.

[Kurt S]

Ric,
G = Detroit Gear and Axle, aka Chevrolet-Detroit Gear and Axle (all the 67-69 literature I've seen shows it as the Detroit Gear and Axle, older lit adds the Chevrolet to the name)
Located just south of Highland Park (where Henry's first Model T plant and former Chrysler HQ were located), just north of downtown Detroit.
Part of American Axle now, I think it's their biggest plant.

Dave,
Thanks! With some care, that should clean up. I would not chop of those monoleaf mounts, they help the value IMO.