8 1/4 gear ratios
This is a MoPar deep chrome pan for the 904 trans. Notice one corner is cut off. Thats the tip you need to know for tranny I.D.
Stock ratios that I know of were as low as 2.45 and up to 3.91 from the factory. If theres not a tag on the rear covers bolt(s) that state the ratio, take a few bucks for a gasket and oil (MoPars whale oil for sure grips if so equiped) and change that oil thats more likely over due for it's change.
While doing this, look on the ring gear for the ratio being stamped in it.
(I hate the guessing game of rotate the whells and driveshaft for a round about guess on the ratio.)