Redline's 79 Trans Am project

[silver_bullet]

https://www.camaros.net/threads/leaf-spring-perch-distance.28642/#lg=thread-28642&slide=0

[silver_bullet]

All the references I’ve found for the NF X 3917124 number cast in the center section appear to be for a Chevelle. Late ‘67 or any 68 based what I’ve read. The build date is 11/08/67 and stamped date is 11/30, So late ‘67 seems likely. Axle shows No signs of being a Chevelle/Malibu rear as there are no upper mounts “ears” as some call them. Definitely smooth axle tubes end to end, so not from any coil spring car either which is what makes it hard to identify. Seems to limit options to another f-body or X body car, but none of the casting number point that way at all.
I’ll have to rig up something to measure wheel mount surface, end to end. Would this be with drums Installed, or axle surface? Fairly certain this 12 bolt is shorter than factory f-body 10 bolt. Someone hammered in a little tire clearance space to the front edge of the rear inner wheel wells. (Rolled the inner edge of rear wheel well/fender too.).
Still searching ...

My best guess would be a 68 (GM would start production of the following model year in October?? of the preceding year) Camaro big block car or Z28.... That axle is slightly shorter than the second gen F body as you mentioned, and is the only Chevrolet car based rear end that would meet that criteria.... Nova was narrower and nearly unheard of for factory 12 bolt (except SS396 model) IIRC...Chevelles were coil spring cars, and Impalas were considerably wider and 5X5 bolt pattern as were the Half ton trucks/vans

[SuperBuickGuy]

with drums on.

[Redline04]

Beyond knowing the date you could probably go by width and general style. Chevelle rears (two different widths depending on year) have cast-in upper trailing arm mounts on the center section, Impalas have them welded to the axle tubes (if cut away the remains may be visible) and F- and X-bodies (again different widths) of-course had leaf springs. Chart from GM 12-Bolt Rearend Guide. How-To Identify That Swap Meet Find (chevyhardcore.com)

All the references I’ve found for the NF X 3917124 number cast in the center section appear to be for a Chevelle. Late ‘67 or any 68 based what I’ve read. The build date is 11/08/67 and stamped date is 11/30, So late ‘67 seems likely. Axle shows No signs of being a Chevelle/Malibu rear as there are no upper mounts “ears” as some call them. Definitely smooth axle tubes end to end, so not from any coil spring car either which is what makes it hard to identify. Seems to limit options to another f-body or X body car, but none of the casting number point that way at all.
I’ll have to rig up something to measure wheel mount surface, end to end. Would this be with drums Installed, or axle surface? Fairly certain this 12 bolt is shorter than factory f-body 10 bolt. Someone hammered in a little tire clearance space to the front edge of the rear inner wheel wells. (Rolled the inner edge of rear wheel well/fender too.).
Still searching ...

[Loren]

Beyond knowing the date you could probably go by width and general style. Chevelle rears (two different widths depending on year) have cast-in upper trailing arm mounts on the center section, Impalas have them welded to the axle tubes (if cut away the remains may be visible) and F- and X-bodies (again different widths) of-course had leaf springs. Chart from GM 12-Bolt Rearend Guide. How-To Identify That Swap Meet Find (chevyhardcore.com)

[Beagle]

I got lazy but looks like it could be from a Chevelle? Search just the "NF 3917124" part. There looks to be a good bit of info that may help you narrow it down. The '68 appears to be the same width as F body, maybe a late '67 build date for a '68 diff...

[DanStokes]

As usual, this level of detail is way out of my league. Hope somebody has a clue.

[Redline04]

Any internet detectives out there? Trying to figure out where the 12 bolt rear in my TA came from. I've narrowed down a few details, but still unknown as to what GM car the axle came from.
Here are the Cast numbers and stamped numbers on the axle...and what info I've found so far.

This Cast number indicates 4.22 gear size carrier. Found on front of lower rt ear on center section (passenger)


This Cast number indicates K-(11th month) 8 = day
7= year 1967

Stamped on front of Rt side axle tube.(Passenger) these indicate: CD = 3.07 posi. 1130B. Means 11th month, 30th day B = Buffalo plant (where it came from)
The E stamped sideways at top of photo indicates Posi gear installed. I am unable to find info on what the Cast numbers/letters indicate on the lower part (hard to read- looks like CON 1 might be OON 1? Last letter could be either N or H?

Can not find any info on this Cast number. Found on front of lower left center section.

So, if anyone can help ID & verify what I'm missing (& what I've found) just trying to narrow down where the axle came from...

[Redline04]

I think the dead give away is that the hub
on the Right,
It only has 3 studs.
And that "Fitted Axle" stub should have been
Easily Seen before the Drums came off.....

Just Saying

Didn’t notice the axle difference until after the drums were off, and That one side (left side) already had one broken stud and one jacked up from someone drilling it. It Appeared to have had a locked up stud or one with wheel locks on it. Both tapped out easily with a 2# hammer, so I plan on replacing all 5 on that side, haven’t gotten to removing the other 3 studs yet. Car Quest stud run in the near future.

[Captain]

I think the dead give away is that the hub
on the Right,
It only has 3 studs.
And that "Fitted Axle" stub should have been
Easily Seen before the Drums came off.....

Just Saying

[Redline04]

And a month later...still at it.

Are brake drums supposed to match?

Removed to clean'em up, turned into "let's just clean up and
repaint the whole rear axle. I'm still puttering around with it 3 weeks later. The Brakes & drums look great, so I just cleaned them up. Noticed one drum seemed to weigh more than the other, so I put'em on a scale. One is 13.4# the other 14.4#
And the axle ends don't match either. Guess this is definitely a hybrid project car.

[Redline04]

New treads mounted & ready to go. Once I get time to clean up the calipers and drums so they look nice behind the new wheels, it's go time.
(Who wants new wheels with grungy looking drums behind them )

[Redline04]

I'm really lucky. My bride wants me to be happy so we set up a deal where I have a monthly allowance for car stuff and I spend it no questions asked. She doesn't "get" the car stuff but she knows it keeps me off the streets and out of the bars.

Me too! The Mrs. knows I only get what I need when I need it, or if it’s a really good deal and I will eventually need it. Plus letting me spend a few $$ on this one keeps me from trying to buy another one. She gets her treats too, so we are both Happy in the long run.

[silver_bullet]

I didn't know that the served caffeine free diet coke in the bars nowadays

They have to so all those college kids can have their no caffeine/diet Coke and Jack cocktails.... on the rocks, only if the ice is made with ultra purified natural sprung water from Fiji...

[cstmwgn]

... keeps me off the streets and out of the bars.

I didn't know that the served caffeine free diet coke in the bars nowadays