yep you can use the same oil in the front and rear diff. Fill them up until the oil drips out the fill hole on the stock diff covers. If there after market covers, yes they can be over filled. Some of the after market covers have a higher fill hole. So go with the recommended amount in the owners manual.

 

Went with Amzoil after 5:13 re-gear dana 30/ 44 rear took just under 3 qts for both. 1.2 front rear about 1.6

 

Just did my diff's yesterday. Both with stock diff covers.

Dana 30 front - took 1 quart
Dana 44 Rear - took 1.7 quarts approx.

Noticed I will have to pick up a good solid rear diff cover or underbelly skid plate for the diff as I got some good rock rash and skinned off 1/2 my bottom bolt which will be a bear to remove...

 

After reading an Amsoil recommendation in a recent issue of Peterson's 4Wheel and Offroad I visited their website and read their gear oil comparison writeup. I was surprised to see the Amsoil outperform some of the higher priced competition. I think I'm going to go with their Severe Gear oil once my break-in period expires.

Out of curiosity--is anyone running their SAE 190 or SAE 250 "Racing Gear Lube"?