what rear diff is under my '49?

this is what came under my '49 chevy 1/2 ton.
i have no clue what it is. any help would be appreciated.

stamped around the pinion area are these codes (not very visible in pictures)

A
C2AW 4668
52
4A13

and on the P*** side of the housing: DIF 30

 

9inch ford

 

Cool. That's what I thought, jus wanted to make sure. Now on to counting for gear ratio.
Thanks.
Chris