Crown gear number decoding (what gear Ratio)

Hi i have a crown gear part # out of a 1972 Charger 9 1/4 rear end. I would like to know what the gear ratio is part # 2852928-271 date coded 2-10-72. Normally in my expeience the ratio is part of the code number. Does anyone have a crown gear casting number decoder?
Thanks
Blair

If it's like an 8.75 gear set, it'll either have the 2 gears tooth count (eg: 41-10), or the actual ratio stamped right on the ring gear (eg: 4.10)