1971 rear end/differential number question

[Paul C.]

My 71 lt-1 number on the housing is SAw or v then 341E2. This indicates a 3.55 rear end. But the casting number is A
12 8. This makes no sense since in 1968 then was no code starting with AA. Any thoughts on what is going on? Are these numbers judged?

[Alan S.]

Re: 1971 rear end/differential number question

Hi Paul,
Sometimes cast 8s and 0s are difficult to differentiate, any chance of that in this case?
How does the A12 work with your car's build date?
Regards,
Alan

[Paul C.]

Re: 1971 rear end/differential number question

Should be AA not SA--a typo. The A 12 fits the Jan 28, 1971 build date. The rear end housing is undercoated from the dealer so it should be original BUT the LT-1 didn't come with a 3.55 rear end. Letters difficult to read.

[Alan S.]

Re: 1971 rear end/differential number question

Hi Paul,
I was suffering from brain freeze… with an A you'd be looking for a 1, not a 0.
Hard to mistake a 1 for a 0!
So…???
Obviously you need help from some who knows what he's talking about… sorry
Regards,
Alan

[Paul C.]

Re: 1971 rear end/differential number question

I was wrong the LT-1 did come with a 3.55 rear end--so the code on the case is correct but the casting date on the cover appears o be wrong. Anyone know were you get the cast iron cover with a more appropriate date? Thanks

[Gary R.]

Re: 1971 rear end/differential number question

Hi Paul
Ikerds would be one source to look for a date coded cover. Probably cost as much as a much better Muskegon HD cover but the date code would be correct.