Gregg1

Hello Putting together a drive 65 roadster .pulled rear end out C clip had come off side shaft ,anyway RH side #3818767 N LH #E274 Is this rear out off a 67? What's the ratio? thanks Gregg

5thvet

The number and letter prefix that you need are actually located on the bottom of the case just forward of where the spring bracket is located. The two letter prefix tells you the ration and the rest is the date.

ricks327

Here is a photo showing what 5thvet referred to, "AM" is the ratio (3:36) then the date.
Rick

wombvette

5-27-64

Gregg1

Thanks ended up with AK 9 2 64 3.36 little disapointed hoped for a little more gear than that ,first corvette I ever owned without Posi thanks Gregg

dkleather

There was no AK code for a 64 date according to my Specifications Guide. The code for a 64 standard/non posi differential would have to be CA, CX or CZ. Are you sure you read the first two numbers correctly? Could the number 64 be a 65?? One or the other seems to be incorrect.
AK code was available beginning 65 through 69 according the guide I have and was a 3:36 non posi unit.

65GGvert

But being a sept 64 date, it could be a very early 65 AK 336 non posi.

Edit, corrected code to AK

dkleather

I agree. I reread the OP's original post and see the code he gave there is 5/27/64 but it's for a yoke. Then under one of the pics he says the date on the case is Sept. 64. That makes complete sense for an early '65.
My Sept.1, 64 has mostly Aug. (H) dated '63 parts. I should have read the post and the date a bit closer!! Dave