[Olatheguy]

Have a new Ford Racing rearend. Planning on running some inexpensive gear oil in it for the first 50 miles or so just to get the gear paint and any other unwanted crud stirred up so I can drain it and then put the Royal Purple in it. Just wanna make sure 80 - 90 gear oil is what I want. ???

[Snake Pliskin]

80-90 should be fine but i'm sure you will need Ford friction modifier for a trac loc diff. The dealership will have it.

[Olatheguy]

yeah ... I already poured that in there. Will have to get another one when I change it though. OReillys had some aftermarket brand but I think I'll go right back with Fords.