Jim,
Glad I could help.
Brian,
To answer your question it is yes and no. This is a standard 9 in. diff housing and chunk but the axles and hubs are not standard. The axles are floating. There is a tube inside the axle tube were the seal is installed. Oil should not be in this tube inner tube. If oil is is in the tube than the seal is leaking. Having said that these seals do not work very well so if you have a small amount of oil in the tube its ok. The reason you do not want oil in the tube is because the wheel bearings run in grease like the front wheel bearings. If the hot oil gets to the outer wheel bearings the oil will melt the grease and you will have bearing failure. The only seal on the outer hub is a paper gasket. So if you have oil leaking out of your hubs it is a mixture of diff oil and melted grease. Not good.
David