In another thread here from many years ago, there was a question posted regarding the ring gear size on a G80 that then determines the exact fluid quantity requirement. The answers were a little confusing and vague to me. How do you determine the ring gear size in a specific Chevrolet vehicle? Some said count the bolts on the differential cover, some said an RPO code and some said through the ID number. Since the level is pretty much the same requirement, just under the fill hole, it's probably not that important but it's one of those 'inquiring minds want to know' things.

Thank you
Richard

(Not verified / copied from post)
8.6" gear = 2.41 quarts
9.5" gear = 2.75 quarts
9.75" gear = 3 quarts
10.5" gear = 2.75 quarts
11.5" gear = 3.83 quarts

 

I just fill'em to the bottom of the hole. RPO will tell you what size and ratio. Yeah bolt count is another way, I'm not up to speed on current truck diff's but old days where 10 or 12 in cars.
Bigger the dif housing the bigger the ring gear.