If you are talking about synthetic gear oil, then, absolutely I would recommend Lucas Synthetic 75W140 and 75W90 gear oils. I use both grades in my '06 Magnum AWD and have seen an increase in 1/4 mile time over Castrol products in the front and rear diffs on the same engine running the exact same fuel (within weeks form the same station), conditions and engine oil (Valvoline SynPower).
So, all-in-all, yes it is a great oil, and I have tried Valvoline Synthetic 75W90 for the front diff, but experienced more wear than the Lucas since my diff upgrades.