as Mongo pointed out, the Dana series will be cast in the case..
and if you're lucky, the ratio tag and limited slip lube tag [if equipped] will be present on cover..
if it's difficult to access or clean well enough to see it, you can measure the cover..
digital phone camera perspective is deceiving, but these are rough measurements;
D44 case model
D44 cover height approx 10" [illustrated as width in chart above]
D44 cover width approx. 9"
D60 case model
D60 cover height approx. 12" [illustrated as width in chart above]
D60 cover width approx. 11"
good luck!