Differential Code Confusion

[Patrick N.]

I could use some help on this,

I checked older threads but still confused-
Can anyone help me de-code my differential build code:
AWW139

Thanks

[Kenneth T.]

Re: Differential Code Confusion

Looks like a 3.08. What year is your car?

[Patrick N.]

Re: Differential Code Confusion

it's a 68 427/400 hp. I'm trying to determine if this is the original rear?

[Terry M.]

Re: Differential Code Confusion

If those are the only stamped numbers on the bottom of it -- it is not. 1968 should have a date stamped into the bottom -- not a code, but a real date -- like: 9 14 68.

I believe someplace on the punkin is a casting number and date. Look for it. I think it is ont he passenger side, but you might wait for others to confirm that is the differential is still int he car. If it is out, you should be able to see the casting number and date more easily.

[Patrick N.]

Re: Differential Code Confusion

I checked the cast number, the case is GM number = 8899143 (possibly 3899143-first num is hard to read).
Casting date code on case is D 4 3,
Casting date code on rear cover is D 2 8

Diff is off of the car and part of frame off restoration.

[Terry M.]

Re: Differential Code Confusion

D 2 8 looks like 1968 code = April 2, 1968

Maybe the case is D 4 8. Threes, sixes and eights can look a lot alike. Or someone else will know about the casting number which may limit the date range.

[John H.]

Re: Differential Code Confusion

I checked the cast number, the case is GM number = 8899143 (possibly 3899143-first num is hard to read).
Casting date code on case is D 4 3,
Casting date code on rear cover is D 2 8

Diff is off of the car and part of frame off restoration.

Patrick -

With those casting dates, the housing looks like a '73 3.08 Posi, cast on April 4, '73, and assembled at Warren in mid-May.

[Patrick N.]

Re: Differential Code Confusion

Thanks everyone for your help!

I do plan to have the car judged- how concerned should I be with finding a correct case? The car came with a HD posi 3.08.1.

Does anyone have a lead to finding a correct case for a 68 mid March car. Crane Corvette?

Thanks again Kenneth, Terry and John.

[John H.]

Re: Differential Code Confusion

I do plan to have the car judged- how concerned should I be with finding a correct case?

Patrick -

Axle "numbers" aren't checked in Flight Judging.

[Patrick N.]

Re: Differential Code Confusion

Done!

Thanks All