Diff numbers

[Twan B.]

Hi,

I've just back from a gay who has a diff for sale. I'am looking for a 3.08:1 diff for my '65 4 speed. (now she has a OA '67) Can anyone tell me somethings about the ## on the diff.
The cast# is :3890143 , date: J267 stamps: OA 3 ?? 7 E 1.
The numbers in the gearwheel "ring" are :3756448 12 3 7 10 77 2
I do believe it is a 3.07 = not a Corvette diff ?????

Thanks,
Twan
#44079

[Joe L.]

Re: Diff numbers

Hi,

I've just back from a gay who has a diff for sale. I'am looking for a 3.08:1 diff for my '65 4 speed. (now she has a OA '67) Can anyone tell me somethings about the ## on the diff.
The cast# is :3890143 , date: J267 stamps: OA 3 ?? 7 E 1.
The numbers in the gearwheel "ring" are :3756448 12 3 7 10 77 2
I do believe it is a 3.07 = not a Corvette diff ?????

Thanks,
Twan
#44079

Twan-----


The 3890143 identifies the casting as a 1967-79 Corvette differential. The "J267" tells us it was cast October 27, 1967 or 1977. In this case, it's 1977 since the "OA" code was not used for 1967 or 1968. The strange thing is that given the October 27, 1977 date, it would have to have been manufactured for the 1978 model year and the "OA" code was not used for 1978. However, it could have been a SERVICE differential assembly or it may be that early 1978 did use 1977 codes.

The 3756448 ring gear does identify it as being a 3.08:1 gear-set.

The only problem you will likely encounter with this differential assuming it's in otherwise good condition is the pinion flange. If it's as-original it will be a flange for use with a 1330 series u-joint. Your 1965 uses a 1310 (old 1280) series u-joint. So, you will either have to change the flange or use a conversion u-joint.