[Held for Ransom]

Just remember. If you can, pop the cover and inspect before purchasing. Bought a '74 Camaro rear end because it was a Posi and 3.42:1 gears. Oops.

[Trevor78]

Sometimes, it's not laziness but the fact the sellers know it's not and act dumb about. Rear-end Hunting sounds like a Popular Gaybar.

[salem1912]

Originally Posted by Trevor78

Sometimes, it's not laziness but the fact the sellers know it's not and act dumb about. Rear-end Hunting sounds like a Popular Gaybar.

Or sitting on the beach with dark sun glasses on.

[Baron Von Zeppelin]

Wow that was a crazy deal . 2.41 vs 3.42

Another fallback is the trusty old spin a lug stud 1 revolution and count pinion revolutions.

[Held for Ransom]

Originally Posted by Baron Von Zeppelin

Wow that was a crazy deal . 2.41 vs 3.42

Another fallback is the trusty old spin a lug stud 1 revolution and count pinion revolutions.

You did the math wrong. The case is still the 410408, 3 series. 41 divided by 11 equals 3.73:1.

['ol Pinion head]

Originally Posted by Baron Von Zeppelin

Wow that was a crazy deal . 2.41 vs 3.42

Another fallback is the trusty old spin a lug stud 1 revolution and count pinion revolutions.

The routine of spinning of the axle & counting the pinion revs, doesnt always work...

As far as a crazy deal. Lot of performarnance coded & single track coded diffs out there with later installed gearsets. Posi units added, posi units robbed.

On the down side, might also find a posi unit with spalled side gears & spider gears. Over the years, so many guys have laid an old assembled rear on the ground next to their garage, barn, etc. Moisture then condenses into the rear, & there will be a heavy rust line on numerous teeth of the ring gear & at
East one or two teeth on the pinion. After a while, some very deep rust pocks in those areas. Smart storage, huh?

Will repeat. always, pull the rear cover & check. Might find something that's a PLUS instead of a deal breaker.

[Baron Von Zeppelin]

Originally Posted by Held for Ransom

You did the math wrong. The case is still the 410408, 3 series. 41 divided by 11 equals 3.73:1.

LoL
think I used 17 and 41 to get that.
Would sure rather get stuck with a 373 than a 241 , not so bad at all.

[unruhjonny]

Originally Posted by 'ol Pinion head

...
Will repeat. always, pull the rear cover & check. Might find something that's a PLUS instead of a deal breaker.

I was trying to figure out your first post;
I had incorrectly assumed that you got burnt by not checking yourself, and were trying to help people from not getting burned themselves.

I did go down the rabbit hole of trying to figure out the housing date code and gear code;
Then tried to figure out what the stamping on the ring gear came out as - but I was unsure which numbers were the ones to use...
The one that really stumped me was the "pumpkin" picture;
What were you trying to show with that one?

That's pretty awesome that you got a 3.73:1 posi - instead of being burned by something much less desirable.

[Trevor78]

Something Something about being sure to check first. Hope the 3.42 wasn't crucial to your plans.

[Held for Ransom]

Originally Posted by Trevor78

Something Something about being sure to check first. Hope the 3.42 wasn't crucial to your plans.

I can live with a 3.42 a lot better than a 3.73. I'd like to think both are more for 4 speeds (but I could live with a 3.42 and auto.) and would like to leave lower gears for the high winding engines.


But now you have me thinking, what's the going price for a good posi rear end?

[400 4spd.]

Originally Posted by 'ol Pinion head

The routine of spinning of the axle & counting the pinion revs, doesnt always work...

As far as a crazy deal. Lot of performarnance coded & single track coded diffs out there with later installed gearsets. Posi units added, posi units robbed.

On the down side, might also find a posi unit with spalled side gears & spider gears. Over the years, so many guys have laid an old assembled rear on the ground next to their garage, barn, etc. Moisture then condenses into the rear, & there will be a heavy rust line on numerous teeth of the ring gear & at
East one or two teeth on the pinion. After a while, some very deep rust pocks in those areas. Smart storage, huh?

Will repeat. always, pull the rear cover & check. Might find something that's a PLUS instead of a deal breaker.

Several years ago I was caught up in a similar situation. A member here brought his F body 3:42 posi to the Charlotte Auto-fair for me to buy. I needed it for a 78 T/A I was restoring for a customer. Claimed it was in good condition.
It was immediately obvious this thing had been in water for some time. The backing plates were rotten on the lower halves, and the sheet metal cover had a rust hole in it. I was treated like a jerk when I politely declined to buy it.

[Held for Ransom]

Originally Posted by unruhjonny

I was trying to figure out your first post;
I had incorrectly assumed that you got burnt by not checking yourself, and were trying to help people from not getting burned themselves.

I did go down the rabbit hole of trying to figure out the housing date code and gear code;
Then tried to figure out what the stamping on the ring gear came out as - but I was unsure which numbers were the ones to use...
The one that really stumped me was the "pumpkin" picture;
What were you trying to show with that one?

That's pretty awesome that you got a 3.73:1 posi - instead of being burned by something much less desirable.

At first I thought you were replying to oPh.
So, I'm one to assume things are correct when purchasing things in a hurry. I found the assembly date/code first. CM (3.42:1 limited slip) G (Buffalo plant) 205 (I think is July 24) 2 (2nd shift) G (I think this one is for the limited slip or I've got the 2 G's reversed). I didn't check the webbing to see if it's '73 or '74 casting. Then on to opening up. A quick look confirmed it was a limited slip unit (410408, with 8's around which I don't know when they came that way). I really didn't start looking at it until I got it home and dumped enough lube to look at the stamped numbers and do the math. Of course the 3/'80 was a major clue too.

[unruhjonny]

sorry, i can now see how that was taken… I’d edit that… but… lol

I had guessed that the “3_80” was a date, but wasn’t sure;
Thank you for explaining the “pumpkin” picture.

I have a 3-series ‘pumpkin’ I pulled from a ‘76 TA the better part of thirty years ago in a smaller plastic container… the only issue with it is (I believe) a cosmetic one;
the pin back out (probably assembled with the lock not installed…
I should share a picture some time…

[poncho-mike]

Years ago I bought a rear end the owner claimed was out of a 1970 GTO Ram III car. The owner claimed it was a 3.55 limited slip, and it had the "N" cast into the top of the pumpkin. I didn't have my axle codes handy, so we pulled the rear cover. The gear set was 10 39. The guy took out a car key and started doing math in the dirt, dividing 39 into 10. He came up with a 2.56. I told him I didn't think he did the math correctly, and he got ticked off and said he could do simple division. So at the risk of making him mad, I didn't argue with him. I got a smoking deal on a 3.90 limited slip. 10 divided by 39 is .256, not 2.56.

[Mr Anonymous]

"Rear end hunting" was the alternate title for my college years.

[kingbuzzo]

jinkies anon...funny story mike

[Bills Auto Works]

Originally Posted by Mr Anonymous

"Rear end hunting" was the alternate title for my college years.

Always been more of a " Hooter Man" but Rear Ends are nice too!

ANYTHING in the "3's" would be considered satisfactory for a Low RPM engine. unless of course those driving don't have the stones for a bit of RPM cruising. 4:11-5:13 for something considered high winding,

God Bless
Bill
https://www.jalopyjournal.com/forum/...closed.614419/

[Trevor78]

Yes, finding something wasn't what you purchased is about having stones, not that you had based your build around a particular gear. Stones it is. As long as you also have the stones to drive your low rpm engine in the 2's.
I shipped a 3.42 rear around the world. It would not have been a good result if any other ratio was found inside, for what I was planning, nor could I sell it to someone with stones and start searching again.
Video hits and marketing has seen what was previously a horrible rear end now become a good one and the easily influenced believe it. I think anyone who's a fan of rear ends is still on the fence with who they belong to, and own a full length mirror.